GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: Boulton on 19 July 2017, 07:42
-
Simple question, what's your opinion on performance fuel? Is it worth paying extra for?
From what some people have said it's not. But others have said to stay away from supermarket fuel and that performance fuel e.g. Shell V-Power would give me extra MPG and make the car run better once I've refilled a few times.
-
I think the second paragraph pretty much sums up the responses you're likely to get. Some are convinced it's worth it to pay extra for premium fuel, others less so.
Mine is only a diesel, but I fill up at Sainsburys usually and have no complaints.
-
Simple question, what's your opinion on performance fuel? Is it worth paying extra for?
From what some people have said it's not. But others have said to stay away from supermarket fuel and that performance fuel e.g. Shell V-Power would give me extra MPG and make the car run better once I've refilled a few times.
My view - complete waste of money .... and here's my theory why ...
People who buy performance fuel are obviously trying to get better performance (mostly in mpg). I think that, even only subconsciously, they will drive slightly differently to try and reinforce their view. They may drive slightly less aggressively etc., and, surprise, surprise, they get a few more mpg.
I think that any performance enhancement will be extremely minor, and much smaller than the natural variation that a driver will get in terms of mpg due to other factors (eg. temperature, traffic conditions, road conditions, rain, wind etc.)
So, my view - all fuels are basically the same ....
... and I'm sure that some people will disagree :smiley:
-
I think tests have been done in the past that show fuels like Shell V Power, BP Ultimate and Tesco Momentum, etc, do have slightly superior properties, however the gains are too small to make any appreciable difference in everyday driving and most petrol cars are setup to run on the 95 octane regular unleaded anyway.
Personally I would always use Shell V Power, but when I see the price compared to supermarket fuel, the Scrooge in me takes over and I fill up with the cheap stuff instead!
-
After the last thread on this topic I was convinced enough to give it a go, the tipping point for me was thar VW do recommend premium fuel in the GTI, 95 is a minimum. I've now been using Tesco Momentum 99 for a few months, long enough to overcome any issues with altering driving behaviour as in TonyJ's post (which by the way I thought a good point) and I have noticed a general improvement in mpg. Not a lot and I haven't done a thorough analysis or anything, it just seems to be that bit ahead in most situations to what I recall last year. Plus, on a full fill up, it's only about £2.50 extra so imho, worthwhile.
-
When I collected mine last Monday I filled up with Sainsbury's Super Unleaded which was £1.08 p/l in Tamworth which I thought was a bargain as we are around £1.10 p/l in Sheffield for std unleaded. I normally use my local Tesco and was meaning to put in the 99 ron stuff which is pretty much the highest octane forecourt fuel but then picked up the normal stuff for my 2nd fill up at the weekend so will probably mix and match depending on how prices are as I don't think most people including me can tell the difference.
-
This old chestnut.
My position is that I use it and have brain washed Mrs LRWmotorsport into using it from day 1 in her (our) CS.
Do I (we) notice any difference? Not in the slightest
Is the higher octane number piece of mind that #2 piston isnt going to melt? Not as much as the VW warranty but the plugs look nice and brown.
Have I been brainwashed by the Oil Company's marketing dept? Probably, but get an extra £1 on my Waitrose voucher every few months.
I know alot about making cars go round corners* and b*gger all about engines. Until our new team was formed and we now have our own engine boffin I used a well known engine builder who's products often take up alot of air-time on ITV4 on Sundays. He said that higher octane pump fuel does make a difference IF: The engine was set up on that fuel eg. Dyno/Designed to run on it OR The engine is highly highly tuned and sensitive to hot spots in the cylinder. In which case refer to the previous statement.
* Typical keyboard warrior claim: Photos of trophy cabinet available up request.
-
You can not go wrong following the Skoda recommended RON for your car, going lower or higher and the ECU should adapt to ensure no engine damage by altering the ignition advance. Lower RON will reduce advance and reduce performance, higher the opposite but the you may not notice the difference in normal driving conditions, but if you drive a little more spirited you probably will.
-
After the last thread on this topic I was convinced enough to give it a go, the tipping point for me was thar VW do recommend premium fuel in the GTI, 95 is a minimum. I've now been using Tesco Momentum 99 for a few months, long enough to overcome any issues with altering driving behaviour as in TonyJ's post (which by the way I thought a good point) and I have noticed a general improvement in mpg. Not a lot and I haven't done a thorough analysis or anything, it just seems to be that bit ahead in most situations to what I recall last year. Plus, on a full fill up, it's only about £2.50 extra so imho, worthwhile.
I currently drive a Polo Blue GT and for the first 5 or 6K miles I only used Tesco Momentum. After this I switched to regular un-leaded and quite soon noticed a 1 or 1.5 mpg improvement (according to dash) in my average fuel consumption. The only thing I can think is that the engine loosened up a bit by this mileage and this was where the improvement came from.
-
5th gear says maybe 2% power boost for about 6-10% more cost. https://www.youtube.com/watch?v=d8L-X89duEs
-
I'll give my answer to the question in the pictorial form.
(https://farm5.staticflickr.com/4206/35444676026_e9a7a6268d_o.jpg) (https://flic.kr/p/W18eiU)
-
Obviously Super Unleaded adds 20% more power, minimum.
-
I use shell v power in my gti not because I think it'll give me more power but because of the cleaning detergents etc. I won't use asda or morrisons ever for the reason they don't put any cleaning detergents in.
-
There is an extensive report conducted by Millbrook Laboratory on behalf of Tesco that compares Tesco 95 & 99 and Shell 95 & 99. It proves the cleaning ability of the better fuels amongst other things.
Link: https://www.tescopfs.com/our-fuels/tesco-momentum99 (https://www.tescopfs.com/our-fuels/tesco-momentum99)
Report: https://d16vpkeamxept2.cloudfront.net/assets/6ca06d648b9541e78fa838fece4a1a23.pdf (https://d16vpkeamxept2.cloudfront.net/assets/6ca06d648b9541e78fa838fece4a1a23.pdf)
For the sake of an extra 5p a litre I always use Tesco 99. VW also recommend 98 or higher in a GTI, why would you ignore a manufacturer recommendation?
http://www.volkswagen.co.uk/need-help/owners/Fuel (http://www.volkswagen.co.uk/need-help/owners/Fuel)
-
I wouldnt put any notice on what 5th gear did in there test. The cars eco needs time to learn what fuel is being used and a couple of spins on a rolling road isn't going to do that.
-
Super unleaded in a GTI? That's news to me... The R, yes, for sure but...
-
For the sake of an extra 5p a litre I always use Tesco 99. VW also recommend 98 or higher in a GTI, why would you ignore a manufacturer recommendation?
http://www.volkswagen.co.uk/need-help/owners/Fuel (http://www.volkswagen.co.uk/need-help/owners/Fuel)
[/quote]
Interesting that the website says that for GTI. Just checked the fuel flap and bit misleading as says Super Unleaded, min 95 Ron?
(http://i1070.photobucket.com/albums/u488/jameshodson1/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg) (http://s1070.photobucket.com/user/jameshodson1/media/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg.html)
-
I was going to say someone should check the flap :)
What does the flap on an R say?
-
Here's one from Mrs LRW's CS.
(https://sitebuilder.freeola.com/media/images/user-images/38604/flap.jpg)
Shamelesly lifted from VW Driver.
It is actually Mrs LRW's flap pictured as Neil forgot to photograph Mr VW's flap for the article
-
For the sake of an extra 5p a litre I always use Tesco 99. VW also recommend 98 or higher in a GTI, why would you ignore a manufacturer recommendation?
http://www.volkswagen.co.uk/need-help/owners/Fuel (http://www.volkswagen.co.uk/need-help/owners/Fuel)
Interesting that the website says that for GTI. Just checked the fuel flap and bit misleading as says Super Unleaded, min 95 Ron?
(http://i1070.photobucket.com/albums/u488/jameshodson1/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg) (http://s1070.photobucket.com/user/jameshodson1/media/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg.html)
[/quote]
The minimum and the recommended don't have to be the same fuel.
The Millbrook report is worth a read too.
-
For the sake of an extra 5p a litre I always use Tesco 99. VW also recommend 98 or higher in a GTI, why would you ignore a manufacturer recommendation?
http://www.volkswagen.co.uk/need-help/owners/Fuel (http://www.volkswagen.co.uk/need-help/owners/Fuel)
Interesting that the website says that for GTI. Just checked the fuel flap and bit misleading as says Super Unleaded, min 95 Ron?
(http://i1070.photobucket.com/albums/u488/jameshodson1/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg) (http://s1070.photobucket.com/user/jameshodson1/media/5CFB3EFD-52C9-48BA-96AE-0B48261F1E86_zpsgksedrow.jpg.html)
The minimum and the recommended don't have to be the same fuel.
The Millbrook report is worth a read too.
[/quote]
Agreed, but the info from VW is different.
Website (as per link posted somewhere above) says "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
Yet fuel flap on mine says 'Super Unleaded, Min 95 Ron'. Is any Super Unleaded less than 97 Ron? Why does it not say Min 98 Ron as per their website?
-
Is any Super Unleaded less than 97 Ron? Why does it not say Min 98 Ron as per their website?
The sticker inside the fuel filler flap is multi-lingual so is used in different countries, and unleaded with an octane rating of 98 might not be available in all countries. I think this is the case in Ireland, where I believe the highest octane rating of unleaded is 95.
-
Looking at the flap photos (fnarr, isn't that what the internet is for :D), notice it says 95 ron is Super and 98 ron is "Super Plus"
I'd ignore the "Super" label and just go by the RON number...
-
i use what the RON rating is on the car, so on the R V-Power, Momentum and BP (if I can't get the other two)
The using what it is tuned for the way forward, when Revo used my Rocco for development and dyne running it used there, 95, 98 and 100 maps on a tank of V Power and you could see the timing pull on the 100 as not up to the mark
in reality my old Polo daily was fed a diet of supermarket 95
-
100 RON is race use isn't it? I don't think you'll find that anywhere other than either in cans or maybe at a circuit.
BP used to make Ultimate 102 though, although it was for motorsport use only and only a few stations used to sell it.
-
Our fuel supplier has a product range of 99 - 119 RON
-
Always run my GTI PP on tesco 99 or shell vpower. Why? Because why not, i love my car and will always give it premium oil, tyres, fuel etc. The cost over a year to use higher RON fuel compared to normal - not enough for me care about.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
All that happens if you don't run it on 98+ ron is it doesn't "FSI" so you lose between 10-30 BHP depending on the model.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
I know, that's what I mean by the info differs from the handbook if I remember correctly. The handbook said don't use it it will not improve the vehicle, the website says 98 is recommended, which must mean it has benefits and will improve?
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
All that happens if you don't run it on 98+ ron is it doesn't "FSI" so you lose between 10-30 BHP depending on the model.
Can you explain how I lose upto 30 bhp, and what FSI that I can't get means? I thought the stratified fuel was used at idle and part throttle to ensure smooth delivery and non strat was then included when at WOT to wash and add fuel. Didn't think it had anything to do with fuel ron...
-
10 - 30 bhp.
Would be really interested to understand a bit more about that.
10 seems excessive, 30 is mind boggling.
Would never have imagined a production engine to be that intolerant to octane number.
Where's the info from? Any links please?
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
All that happens if you don't run it on 98+ ron is it doesn't "FSI" so you lose between 10-30 BHP depending on the model.
Can you explain how I lose upto 30 bhp, and what FSI that I can't get means? I thought the stratified fuel was used at idle and part throttle to ensure smooth delivery and non strat was then included when at WOT to wash and add fuel. Didn't think it had anything to do with fuel ron...
Well I'm no auto technician so you probably know more than me. The training from years ago told me it was more to do with the sulpher content of the fuel and the quality of the fuel. As FSI relies on injecting fuel at the last second to produce a bigger bang and therefore more power for it to work properly it requires the right type of fuel so for FSI engines we were told to recommend super. We were told if super/low sulpher fuel wasn't used then the engine would still work but wouldn't FSI meaning the improvement in BHP for the FSI engines simply wouldn't be there. This improvement equated to about 10%, for example a 1.6 petrol had 105ps but with FSI tech had 115ps.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
All that happens if you don't run it on 98+ ron is it doesn't "FSI" so you lose between 10-30 BHP depending on the model.
I’m sorry but i don’t believe that for one second.
-
@Mattwilko92
I think ppl are prepared to use better tyres or oil as it will have benefits, however the fuel was (as stated in the handbook) suggested to only have an effect on the R, and not the GTi. If VW have updated this advice it is interesting and something to try, but many original decisions were based on the handbook advice which said "don't bother" if i remember correctly.
I am one who has used these fuels in the past in UK and Europe on cars (think its 102ron in Germany at the Ring) But didn't bother in the GTi as I mentioned above.
The VW UK website says: (as per link posted somewhere above) "For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON)."
From the horses mouth, so to speak.
All that happens if you don't run it on 98+ ron is it doesn't "FSI" so you lose between 10-30 BHP depending on the model.
I’m sorry but i don’t believe that for one second.
Could well all be nonsense but that's what we get told
-
The cost over a year to use higher RON fuel compared to normal - not enough for me care about.
For 10,000 miles a year - around £136 based on current figures (113p/l for 95, 122p/l for V-power).
-
The cost over a year to use higher RON fuel compared to normal - not enough for me care about.
For 10,000 miles a year - around £136 based on current figures (113p/l for 95, 122p/l for V-power).
Or buy Tesco 99 @ 115.9/litre at the moment :grin:
-
The cost over a year to use higher RON fuel compared to normal - not enough for me care about.
For 10,000 miles a year - around £136 based on current figures (113p/l for 95, 122p/l for V-power).
Or buy Tesco 99 @ 115.9/litre at the moment :grin:
Exactly (both of you) - considering how much people will pay for dubious performance upgrades this is a bit of a bargain! For me, at around 8k miles per year on Tesco 99, it works out at less than £5 a month :smiley:
-
Camp I'm in.
(http://i.imgur.com/ETV3Mup.jpg)
:grin:
-
The cost over a year to use higher RON fuel compared to normal - not enough for me care about.
For 10,000 miles a year - around £136 based on current figures (113p/l for 95, 122p/l for V-power).
Or buy Tesco 99 @ 115.9/litre at the moment :grin:
Exactly (both of you) - considering how much people will pay for dubious performance upgrades this is a bit of a bargain! For me, at around 8k miles per year on Tesco 99, it works out at less than £5 a month :smiley:
Agreed. :cool:
-
I've only ever used standard fuel but I think I'm going to upgrade from now on.
I do less than 5000 miles a year so it won't break the bank :smiley:
-
I've only ever used standard fuel but I think I'm going to upgrade from now on.
I do less than 5000 miles a year so it won't break the bank :smiley:
That equates to a very reasonable £2.75 a month, there or thereabouts :grin: Or put another way, 1/2 a pint less per month in the pub. But if I were you, I'd save the money bi-monthly as half a proper drink just doesn't look right....:whistle:
-
I've only ever used standard fuel but I think I'm going to upgrade from now on.
I do less than 5000 miles a year so it won't break the bank :smiley:
That equates to a very reasonable £2.75 a month, there or thereabouts :grin: Or put another way, 1/2 a pint less per month in the pub. But if I were you, I'd save the money bi-monthly as half a proper drink just doesn't look right....:whistle:
I get 2 pints for£2.75 in Salford :wink:
-
I've only ever used standard fuel but I think I'm going to upgrade from now on.
I do less than 5000 miles a year so it won't break the bank :smiley:
That equates to a very reasonable £2.75 a month, there or thereabouts :grin: Or put another way, 1/2 a pint less per month in the pub. But if I were you, I'd save the money bi-monthly as half a proper drink just doesn't look right....:whistle:
I get 2 pints for£2.75 in Salford :wink:
Hmmm, what's the job and housing situation like round there? :laugh:
-
I'm lying of course, it costs a small fortune to get pissed up north these days :laugh:
-
I've only ever used standard fuel but I think I'm going to upgrade from now on.
I do less than 5000 miles a year so it won't break the bank :smiley:
That equates to a very reasonable £2.75 a month, there or thereabouts :grin: Or put another way, 1/2 a pint less per month in the pub. But if I were you, I'd save the money bi-monthly as half a proper drink just doesn't look right....:whistle:
Yeah but you live down in that London.
-
In case anyone is interested - from my 20 plate GTI
(https://i.postimg.cc/YqNKF6n3/IMG-1980.jpg) (https://postimg.cc/zVfcZg1b)
does that contradict current VW recommendation of For most vehicles standard unleaded is fine (95RON) but for GTI and 'R we recommend super unleaded (98RON).? I am currently on normal shell but toying with super unleaded 98 ron plus fuel but not so sure now??
-
Shell v power won't necessarily make it go faster but it's the cleaning additives that will help long term compared to standard stuff.
-
min 95 ? any thing higher better :wink:
smoother and better mpg with v power no brainer
-
min 95 ? any thing higher better :wink:
smoother and better mpg with v power no brainer
Min 95 and anything higher is OK too, but won't improve performance or economy. EA888 is set up for 95, EA113 is set up for 97+.
The EA888 won't compress 97/98/99 any further than it would 95, 99 is no more calorific than 95, in some cases it is less energy dense because they use more ethanol content to raise the RON number and ethanol only has 2/3 the fuel density.of petrol- so no performance gains or fuel economy gains to be had. A 95 RON optimised engine doesn't run better on RON99.
As an aside, I saw a YouTube video with a US guy who seems to be a VW nut. He opened up the intake of his 10000 miles old GTI (EA888 v3) and the backs of the valves and seats were quite gummed up with carbon (more tar like than hardened carbon) already - especially for cylinders 2 and 3.
-
The US version of the EA888 doesn't have the port injection so this will add to the carbon build up process.
-
The US version of the EA888 doesn't have the port injection so this will add to the carbon build up process.
Neither does the European one for those Golf GTIs new enough to have a GPF fitted. EA888 3b (Budack cycle capable) as found on Arteon and Passat (190ps 2.0TSI) and on Polo GTI (200ps) still have port injection in addition to direct injection.
-
min 95 ? any thing higher better :wink:
smoother and better mpg with v power no brainer
Min 95 and anything higher is OK too, but won't improve performance or economy. EA888 is set up for 95, EA113 is set up for 97+.
The EA888 won't compress 97/98/99 any further than it would 95, 99 is no more calorific than 95, in some cases it is less energy dense because they use more ethanol content to raise the RON number and ethanol only has 2/3 the fuel density.of petrol- so no performance gains or fuel economy gains to be had. A 95 RON optimised engine doesn't run better on RON99.
As an aside, I saw a YouTube video with a US guy who seems to be a VW nut. He opened up the intake of his 10000 miles old GTI (EA888 v3) and the backs of the valves and seats were quite gummed up with carbon (more tar like than hardened carbon) already - especially for cylinders 2 and 3.
Thanks - any idea why VW say they recommend 98 ron then - all seems a bit odd?
-
As an aside, I saw a YouTube video with a US guy who seems to be a VW nut. He opened up the intake of his 10000 miles old GTI (EA888 v3) and the backs of the valves and seats were quite gummed up with carbon (more tar like than hardened carbon) already - especially for cylinders 2 and 3.
I just seen that video: https://www.youtube.com/watch?v=CB5ThYfX7ag
That's a lot of build up for 10k miles considering it has a catch can and he has changed the oil twice since new. Feeding it nothing but vPower hasn't prevented the injectors getting quite mucky as well.
-
The US version of the EA888 doesn't have the port injection so this will add to the carbon build up process.
Neither does the European one for those Golf GTIs new enough to have a GPF fitted. EA888 3b (Budack cycle capable) as found on Arteon and Passat (190ps 2.0TSI) and on Polo GTI (200ps) still have port injection in addition to direct injection.
Indeed, I'm glad I have the pre GPF version :smug:
-
min 95 ? any thing higher better :wink:
smoother and better mpg with v power no brainer
Min 95 and anything higher is OK too, but won't improve performance or economy. EA888 is set up for 95, EA113 is set up for 97+.
The EA888 won't compress 97/98/99 any further than it would 95, 99 is no more calorific than 95, in some cases it is less energy dense because they use more ethanol content to raise the RON number and ethanol only has 2/3 the fuel density.of petrol- so no performance gains or fuel economy gains to be had. A 95 RON optimised engine doesn't run better on RON99.
As an aside, I saw a YouTube video with a US guy who seems to be a VW nut. He opened up the intake of his 10000 miles old GTI (EA888 v3) and the backs of the valves and seats were quite gummed up with carbon (more tar like than hardened carbon) already - especially for cylinders 2 and 3.
Thanks - any idea why VW say they recommend 98 ron then - all seems a bit odd?
Do they? Where do they say that? Go with the guidance on the fuel filler flap sticker.
For EA888, that's "minimum 95RON" i.e. for markets where lower RON fuel is available, don't go lower. You can go higher, with no tangible performance/economy benefits.
If you have EA113 (R, CS, CSS, TCR, Audi S3, Leon Cupra), they recommend 98RON. It's not obligatory because VAG acknowledge that 98RON+ might not be widely available in some markets. If you stick 95RON into the aforementioned EA113 variants, the ECU will detect its use and adjust timing accordingly to prevent knocking and reduce the power accordingly (to about 285ps, I believe) because you can't inject that much 95RON fuel into the engine in the conditions required to run at 300ps max without it pinking. That's primarily the reason you generally don't see lower output cars with requirements for 98RON, unless the engine is running a high compression ratio all the time.
-
As an aside, I saw a YouTube video with a US guy who seems to be a VW nut. He opened up the intake of his 10000 miles old GTI (EA888 v3) and the backs of the valves and seats were quite gummed up with carbon (more tar like than hardened carbon) already - especially for cylinders 2 and 3.
I just seen that video: https://www.youtube.com/watch?v=CB5ThYfX7ag
That's a lot of build up for 10k miles considering it has a catch can and he has changed the oil twice since new. Feeding it nothing but vPower hasn't prevented the injectors getting quite mucky as well.
Yep, surprised me too. One thing about that video - he makes it clear that it's a Golf R he's working on (the twin pipes seen on the LHS of the rear bumper would back that up), but he's talking about it being an EA888 engine. Bit confused by that unless they have something like a 280ps EA888 based R rather than a 300ps EA113 R in the US because they have much less access to high RON fuel, with most of their cars being lazy low compression ratio V6 and V8s? Or maybe a genuine slip of the tongue and his was an EA113 R?
-
They don't use ea113 engines in Rs or CS or even gtis do they? They are all ea888.
-
They don't use ea113 engines in Rs or CS or even gtis do they? They are all ea888.
You're right. Thought R still had EA113 (as per MK6), but after looking into it, they're all EA888. There'll still be some differences between higher output (CS/CSS/R/TCR and S3) and standard (245ps) for the higher output variants to be optimised for 97/98/99RON with the ability to drop performance for 95RON use.
APR state the following differences for 2019 R vs 2019 GTI:-
Cylinder head (made from a different alloy compared to other engines in this module because of higher thermal stress)
Exhaust valves (hollow, higher Ni content, nitrided)
Exhaust valve seat rings (improved temperature stability and wear resistance)
Exhaust camshaft (adapted valve timings)
Compression ratio 9.3:1 with different pistons
Piston cooling jets (higher flow rate)
High pressure injectors (even higher flow rate)
Exhaust turbocharger
Charge pressures of up to 17.4 PSI (1.2 bar)
High performance main radiator with 1-2 auxiliary radiators (depending on country specifications)
Additional acoustic modifications have been made in order to achieve a sporty sound - use of a sound actuator (for the occupant cell) and active exhaust flaps in the exhaust system
There's no reason for RON99 fuel to cost any more than RON95. There's nothing in there upping the RON that's any more expensive than the constituents of 95RON. There's just the marketing opportunity to charge more for something perceived as better. They justify the difference with detergent additions. Doesn't account for any meaningful price hikes, assuming that the 95RON fuel doesn't have the same level of detergents.
-
Surprised this is still a "debate"..
The higher the octane the more complete the burn & the less the emissions will be...
I've been using Shell Vpower (optimax etc) since it was first available where I am (since well over a decade ago).....
Years ago EVO mag did a proper long term test on several different cars (turbo & nat asp) including borescope inspections & dyno runs etc...& proved that it did make a difference to the engine output as well as response, better economy & cleaner engine insides...
Google brings this huge thread (read the first post) up on a Skoda forum which refences tests etc done by UK based tuners (Thorney Motorsport)..& proves again that higher octane is better...
https://www.briskoda.net/forums/topic/222948-proof-that-99-ron-massively-outperforms-95-ron/
-
^ All that set of studies really shows is that cars designed to run on RON 98, will underperform using RON95. That's a given. Every single car mentioned in that study is meant to be using higher octane fuel and is down on power when running on RON95 because the ECU retards the timing to make ignition happen sooner in the compression cycle to avoid pre-ignition.
Putting RON98/99 in a car optimised for RON95 will not see appreciable gains in output or economy.
Putting RON99 fuel in a RON95 optimised car may result in a marginally less efficient burn because the fuel is nowhere near the threshold for self detonation. You end up with a slightly less energetic fuel/air mix at the point of spark induced ignition. The differences are small and won't make much difference.
Higher octane fuels are less volatile so that they can be compressed further without preignition. High octane optimised cars run a higher effective compression ratio like for like than those optimised for RON95 fuel.
With variable valve opening and other technologies, RON95 cars can mimic effectively higher compression ratios under very low loads where the fuel:air mix is very lean and unlikely to pre-ignite under the higher effective compression ratio, for economy gains. The Budack cycle mode on the EA888 3b is a prime example.
In much the opposite way, diesel engines could make better use of diesel fuel that is a little more volatile, so higher cetane numbers give a more volatile diesel for a fuller combustion.
If RON95 optimised cars (like the GTIs running lower than the CS) could harness greater gains from running on RON98/99 fuel by detecting the fuel difference and advancing the timing and compressing the fuel further under a higher effective compression ratio, VW would be putting recommendations on the fuel filler cap to use RON98/99, but they don't.
-
Putting RON98/99 in a car optimised for RON95 will not see appreciable gains in output or economy.
Putting RON99 fuel in a RON95 optimised car may result in a marginally less efficient burn because the fuel is nowhere near the threshold for self detonation. You end up with a slightly less energetic fuel/air mix at the point of spark induced ignition. The differences are small and won't make much difference.
Some of the cars that Evo did the test on basically had "95RON" on the fuel filler caps.....& the MR2 in the above Thorney motorsports test isn't exactly a "98Ron only" candidate... unlike the BMW M3 CSL
& please explain why my MK7 Golf "95Ron" 1.4lt which should have 140ps (138bhp) & 250Nm actually has 167bhp & 267Nm....from Shell vpower & a drop in ITG tri layer foam air filter....if the fuel will do nothing??
-
Putting RON98/99 in a car optimised for RON95 will not see appreciable gains in output or economy.
Putting RON99 fuel in a RON95 optimised car may result in a marginally less efficient burn because the fuel is nowhere near the threshold for self detonation. You end up with a slightly less energetic fuel/air mix at the point of spark induced ignition. The differences are small and won't make much difference.
Some of the cars that Evo did the test on basically had "95RON" on the fuel filler caps.....& the MR2 in the above Thorney motorsports test isn't exactly a "98Ron only" candidate... unlike the BMW M3 CSL
& please explain why my MK7 Golf "95Ron" 1.4lt which should have 140ps (138bhp) & 250Nm actually has 167bhp & 267Nm....from Shell vpower & a drop in ITG tri layer foam air filter....if the fuel will do nothing??
There are a number of reasons for your power/torque increase over book:
1. VW are notorious for Conservative power/torque values. Most are over book from the get-go and improve more when running in.
2. Many dynos over-read to flatter the client- it's the difference between the before and after (remaps etc.) that counts).
3. Do you think your filter is doing anything for your output? It's a contributory factor. You can't attribute gains to one variable.when there are multiple variables to consider, unless you've eliminated one at a.time.
Even though.VW outputs are Conservative, I'm dubious that your car is outputting 21% more power over spec, but correspondingly only 7% more torque. More likely putting out 150- 155ps and that dyno is drastically over-reading for the rest.
To quantify your gains that you attribute to the fuel and filter, you should dyno stock with 95RON fuel, then dyno with new filter and 95RON fuel, then dyno again with 98/99RON fuel on the same dyno and note the differences between them.
By your reckoning, there's no need to buy a TCR, just put your filter in a 245ps GTI performance, fill up with Shell V Power and you'll get 296ps.
Not buying it.
Cars set up for RON98/99 can retard timing to run on the lesser stuff at reduced output. Cars set up for RON95 don't advance timing to gain meaningful amounts of power using RON98/99 fuel, which means the extra compressibility of the higher octane fuel is not being utilised.
-
Do they? Where do they say that? Go with the guidance on the fuel filler flap sticker.
https://www.volkswagen.co.uk/need-help/need-help-faqs/owners/Fuel
-
Even if it’s a placebo, I enjoy looking after my cars, so it’s always Shell V Power for me and has been for a few years. I’m not that arsed about economy (its a GTI - it’s supposed to be fun and before the GTI I had a D3 and a D4 Discovery and they have a serious lack of fuel economy) but I am keen to keep everything in the best mechanical order possible - so you pay your money, you take your choice- happy motoring.
-
I wonder if the additional additives in vpower will help gpf cars that are no longer dual port?
-
There are a number of reasons for your power/torque increase over book:
1. VW are notorious for Conservative power/torque values. Most are over book from the get-go and improve more when running in.
2. Many dynos over-read to flatter the client- it's the difference between the before and after (remaps etc.) that counts).
Even though.VW outputs are Conservative, I'm dubious that your car is outputting 21% more power over spec, but correspondingly only 7% more torque. More likely putting out 150- 155ps and that dyno is drastically over-reading for the rest.
Not buying it.
Cars set up for RON98/99 can retard timing to run on the lesser stuff at reduced output. Cars set up for RON95 don't advance timing to gain meaningful amounts of power using RON98/99 fuel, which means the extra compressibility of the higher octane fuel is not being utilised.
For starters the figures I stated are not Dyno..they are direct readouts on live road data from the ECU...Torque is a direct ECU readout parameter...BHP is accurately calculated from various other sensors/data ..& more accurate than a rolling road dyno as no tyre slip..
My engine is an EA211 light pressure turbo, and bhp will increase easily compared to torque.
I also know of several other EA211 140/150PS engines which have had dyno results before & after remaps…& those which run on 98/99RON BEFORE the remaps always run more BHP & torque than those which are just run on 95RON before the remap....& that's in different countries & dynos & the trend is the same...& those which run 95RON are always close to book figures, or only a few bhp over...
You miss that the fuel door sticker states "95RON Min"...basically that's the lowest grade fuel the ECU will cope with.
The ECU is programmed to respond to 98/99RON grade fuels...& the exhaust cam shaft is variable by 40deg & the inlet camshaft by 50deg...so that's plenty of range to allow the ECU to fully use the advantage of high octane fuel....
-
Do they? Where do they say that? Go with the guidance on the fuel filler flap sticker.
https://www.volkswagen.co.uk/need-help/need-help-faqs/owners/Fuel
That’s what I was trying to get at - why do they put they recommend 98 ron on their website but on the fuel filler cap at least with the 20 plate models it say 95 ron ? It just seems Contradictory
-
My TCR on the filler cap says 98 RON, min 95 whereas the GTIPP I had said 95 RON min. So the TCR should be 98 but you can get away with 95 whereas a GTIPP will be fine on 95 but 98 would be better. Does it really need to be made any more confusing than that?
-
Do they? Where do they say that? Go with the guidance on the fuel filler flap sticker.
https://www.volkswagen.co.uk/need-help/need-help-faqs/owners/Fuel
That’s what I was trying to get at - why do they put they recommend 98 ron on their website but on the fuel filler cap at least with the 20 plate models it say 95 ron ? It just seems Contradictory
That is a very general bit of blurb on their website, it's not even model specific. It says all VWs are fine on 95, with recommendation for 98 for GTI and R. Taking that as read, they recommend RON98 on the Up! GTI 1.0TSI 116ps.
If you look in the technical bits of the brochures (not the pricelists), it tells you what the recommended minimum. Fuel is. Can't find a very recent MK7 one, but the 2015 one shows 220ps and 230ps stating RON95, and R stating RON98 - same differentiation as you'd find on your fuel filler cap sticker. It states minimum because if you could only find RON98/99 fuel to fill up your RON95 optimised car, it reassures that you won't damage your car using it. It won't advance the timing to compress it further than it would compress RON95 fuel.
-
My TCR on the filler cap says 98 RON, min 95 whereas the GTIPP I had said 95 RON min. So the TCR should be 98 but you can get away with 95 whereas a GTIPP will be fine on 95 but 98 would be better. Does it really need to be made any more confusing than that?
GTI PP won't be better on RON98. The only reason the TCR needs RON98 is that it has been set up with the capability to squirt enough fuel in per compression cycle to achieve 290ps, and the PP hasn't.
As said before, RON98/99 fuel is NO MORE ENERGY DENSE than RON95, but it is less volatile, so you can compress and ignite more of it per compression cycle.
The ECU is set up on each car with a map that manages fuelling - so at full tilt, the TCR/R will be combusting more fuel than the PP at full tilt. Just because you fill your GTI PP with RON98 fuel, the ECU isn't going to decide to suddenly unlock TCR/R levels of fuelling to allow you to get to 290ps. A 230ps PP on RON95 will be 230ps on RON98 because it won't take any more fuel in.
You need to increase your fuelling to increase your bhp. Running your stock PP on RON98 makes no sense for gains, running your remapped PP on RON98 makes perfect sense to prevent pinking with the amount of fuel that 300ps PP will be chucking in at full tilt.
-
maybe I'm missing some thing or some of you guys are more technically minded than me. But the octane rating is the temperature that the fuel ignites under compression. The higher the temp, the bigger and cleaner the bang, given improved power and emissions.
-
maybe I'm missing some thing or some of you guys are more technically minded than me. But the octane rating is the temperature that the fuel ignites under compression. The higher the temp, the bigger and cleaner the bang, given improved power and emissions.
You are correct. You can compress an air/fuel mix further, generating more heat, if that fuel has a higher RON number. Not a hell of a lot of difference between a RON95 optimised car and a RON98 optimised car for effective compression ratio (about 10:1 max for RON95, 11.5:1 max for RON99 and 25:1 max for diesel), so efficiency differences are marginal.
The difference between a petrol and diesel engine air:fuel mix pressure/temperature is huge. Diesel is compressed much further, self igniting at a much higher temperature to make a bigger bang and converting more of that bang to kinetic energy. Diesels also run with air at a large excess, which is not the case with petrols.
However, people generally assume that RON98/99 fuel has more chemical energy per litre than RON95. It doesn't, and in many cases the higher RON fuel is less energy dense. Ethanol has a much higher RON number than petrol, so it's often used to increase RON number in higher octane fuels. RON95 is typically E5 rated (5% Ethanol), RON99 is often E10 (10% ethanol). Ethanol only has 2/3 the fuel density of undiluted (no ethanol content) petrol. So E10 petrol has around 98.5% of the energy density of E5 petrol.
For a car optimised for RON99, burning that RON99 E10 fuel, it needs to be burning it marginally more efficiently than a RON95 optimised car burning RON95 E5 fuel to match it in mpg. This lower fuel density burned in a marginally cleaner way under higher pressure cancels out.
As you use more throttle and fuel per ignition cycle, there's a limit to how far you can compress that fuel:air mix, so cars optimised for RON95 have less fuel in at max output than RON98 optimised cars. This is why the likes of the TCR and R need RON98 fuel to attain their max outputs because the amount of fuel required would cause pre-ignition if that fuel were RON95.
Due to this limit on how much fuel a RON95 optimised car is metered to add per ignition cycle, there is no need to advance the timing to compress the fuel further if the car is being fuelled with RON98.
-
For starters the figures I stated are not Dyno..they are direct readouts on live road data from the ECU...Torque is a direct ECU readout parameter...BHP is accurately calculated from various other sensors/data ..& more accurate than a rolling road dyno as no tyre slip..
My engine is an EA211 light pressure turbo, and bhp will increase easily compared to torque.
I also know of several other EA211 140/150PS engines which have had dyno results before & after remaps…& those which run on 98/99RON BEFORE the remaps always run more BHP & torque than those which are just run on 95RON before the remap....& that's in different countries & dynos & the trend is the same...& those which run 95RON are always close to book figures, or only a few bhp over...
You miss that the fuel door sticker states "95RON Min"...basically that's the lowest grade fuel the ECU will cope with.
The ECU is programmed to respond to 98/99RON grade fuels...& the exhaust cam shaft is variable by 40deg & the inlet camshaft by 50deg...so that's plenty of range to allow the ECU to fully use the advantage of high octane fuel....
The ECU doesn't throw more fuel in on a RON95 optimised car if RON98 fuel were to be detected. As RON98 fuel is no more calorific than RON95 fuel, the output does not increase in using the same amount of RON98 fuel. If it did, the car would have 2 published outputs - 1 for RON95 usage and 1 for RON98 usage. TCR/CSS/R need more fuel to achieve 290/300/310ps than a GTI performance needs to achieve 245ps output. The amount of fuel a GTI Performance needs to max out can be handled without pinking, using RON95 fuel. Not the case for TCR/CSS/R - hence they need to use RON98 fuel.
How do you get these torque and power figures from the ECU without the need of a dyno. Genuinely interested in finding out what my car does without putting it on a dyno. VCDS? OBD11?
Min values on fuel cap to denote minimum RON value. There's no insinuation in any VW literature that you'll increase your bhp with higher octane fuels, and certainly not 21% over stock. If your car is performing that well, it'll be down to VW understating published output and having been run in well.
-
Now I'm confused! Is a standard 7.5 GTI optimized for 98ron with a minimum of 95ron. Or is it optimized for 95ron?
-
I wonder if the additional additives in vpower will help gpf cars that are no longer dual port?
Doubtful Chris, you need port injected fuel vapour washing the backs of the intake valves to keep them clean. The American YouTuber was using V-power exclusively and still had gummy valves at 10k miles and slightly crappy injectors.
You should be using higher octane fuel in your TCR though anyway.
-
Now I'm confused! Is a standard 7.5 GTI optimized for 98ron with a minimum of 95ron. Or is it optimized for 95ron?
It's optimised for RON95. Output figures are for RON95 fuel and the engine won't give you any more power for burning the same amount of RON98 fuel using the ignition timings it would use for RON95 fuel. it won't advance the timing to RON98 optimised engine settings either. There's no advantage for the engine to do so.
A TCR/CSS/R can use 95RON and have its top end curtailed to about 285ps to prevent pinking at the top end. The opposite is not true. You can't take a stock 220/230/245ps GTI, feed it RON98 fuel and effectively get a free remap because it'll now decide it can be fuelled more at the top end to increase output.
-
I wonder if the additional additives in vpower will help gpf cars that are no longer dual port?
Doubtful Chris, you need port injected fuel vapour washing the backs of the intake valves to keep them clean. The American YouTuber was using V-power exclusively and still had gummy valves at 10k miles and slightly crappy injectors.
You should be using higher octane fuel in your TCR though anyway.
how do you stop it from getting the carbon build up? It's the only concern I've got when I get my car. Any other tips/methods etc?
-
The ECU doesn't throw more fuel in on a RON95 optimised car if RON98 fuel were to be detected. As RON98 fuel is no more calorific than RON95 fuel, the output does not increase in using the same amount of RON98 fuel. If it did, the car would have 2 published outputs - 1 for RON95 usage and 1 for RON98 usage. TCR/CSS/R need more fuel to achieve 290/300/310ps than a GTI performance needs to achieve 245ps output. The amount of fuel a GTI Performance needs to max out can be handled without pinking, using RON95 fuel. Not the case for TCR/CSS/R - hence they need to use RON98 fuel.
How do you get these torque and power figures from the ECU without the need of a dyno. Genuinely interested in finding out what my car does without putting it on a dyno. VCDS? OBD11?
Min values on fuel cap to denote minimum RON value. There's no insinuation in any VW literature that you'll increase your bhp with higher octane fuels, and certainly not 21% over stock. If your car is performing that well, it'll be down to VW understating published output and having been run in well.
I used a stand alone device called Autopolar which connected to the OBD port & read the data...I have full unlimited VIN VCDS which will do the same...there is another device called Vector (I think) which will do the same....the data has always been there...there is a thread on an Audi forum that's years old which went into details of creating Excel spreadsheets for logging in VCDS for bhp & torque & creating graphs...eg dyno sheets...
Back to fuels & ECUs
The ECU is programmed with the various responses to the available fuels in its sales country, this is why it states the "95RON MIN" or "98RON MIN".....& other countries for the same engine will state "91RON MIN".
The ECU is written with a lot of parameters, & most of the fueling is controlled by two main parameters, knock sensors (pre-detonation)..& Lambda levels..(% scub of the exhaust gases registered between the two Lambda sensors).
Basically & simply put it has no idea what fuel you have put in, but it LOOKS at how the fuel has combusted, in the terms of two questions:- "can I advance/retard the timing & how much before I get knock?"...The second question it asks is "is the burn/emissions within the stochiometric parameters?".
The higher the octane rating the HARDER it is for the fuel to ignite.....this means LESS auto-detonation….(knock)...this also means more heat & energy is required to ignite it..this is why better ignition systems are required..with a more powerful & open spark.
Conversely it means that when the engine is hot & under load & at higher rpm, the ECU can better "open up" the timing/fueling until it hits the prewritten parameter end values in the ECU data by using a cleaner & more COMPLETE burn fuel like 98RON...compared to 95RON...
This is why in my car running Vpower (used as an example) it now generates MORE %BHP than torque increase over factory....its working rate has improved more, but the FORCE twisting the crankshaft (torque) has not increased much....thus the car is more responsive when you floor it....
-
The ECU doesn't throw more fuel in on a RON95 optimised car if RON98 fuel were to be detected. As RON98 fuel is no more calorific than RON95 fuel, the output does not increase in using the same amount of RON98 fuel. If it did, the car would have 2 published outputs - 1 for RON95 usage and 1 for RON98 usage. TCR/CSS/R need more fuel to achieve 290/300/310ps than a GTI performance needs to achieve 245ps output. The amount of fuel a GTI Performance needs to max out can be handled without pinking, using RON95 fuel. Not the case for TCR/CSS/R - hence they need to use RON98 fuel.
How do you get these torque and power figures from the ECU without the need of a dyno. Genuinely interested in finding out what my car does without putting it on a dyno. VCDS? OBD11?
Min values on fuel cap to denote minimum RON value. There's no insinuation in any VW literature that you'll increase your bhp with higher octane fuels, and certainly not 21% over stock. If your car is performing that well, it'll be down to VW understating published output and having been run in well.
I used a stand alone device called Autopolar which connected to the OBD port & read the data...I have full unlimited VIN VCDS which will do the same...there is another device called Vector (I think) which will do the same....the data has always been there...there is a thread on an Audi forum that's years old which went into details of creating Excel spreadsheets for logging in VCDS for bhp & torque & creating graphs...eg dyno sheets...
Back to fuels & ECUs
The ECU is programmed with the various responses to the available fuels in its sales country, this is why it states the "95RON MIN" or "98RON MIN".....& other countries for the same engine will state "91RON MIN".
The ECU is written with a lot of parameters, & most of the fueling is controlled by two main parameters, knock sensors (pre-detonation)..& Lambda levels..(% scub of the exhaust gases registered between the two Lambda sensors).
Basically & simply put it has no idea what fuel you have put in, but it LOOKS at how the fuel has combusted, in the terms of two questions:- "can I advance/retard the timing & how much before I get knock?"...The second question it asks is "is the burn/emissions within the stochiometric parameters?".
The higher the octane rating the HARDER it is for the fuel to ignite.....this means LESS auto-detonation….(knock)...this also means more heat & energy is required to ignite it..this is why better ignition systems are required..with a more powerful & open spark.
Conversely it means that when the engine is hot & under load & at higher rpm, the ECU can better "open up" the timing/fueling until it hits the prewritten parameter end values in the ECU data by using a cleaner & more COMPLETE burn fuel like 98RON...compared to 95RON...
This is why in my car running Vpower (used as an example) it now generates MORE %BHP than torque increase over factory....its working rate has improved more, but the FORCE twisting the crankshaft (torque) has not increased much....thus the car is more responsive when you floor it....
I completely get what you're saying, but it's as much about the chemistry of combustion as the engineering of the car.
There's no way you can seriously attribute your 1.4 Golf apparently overperforming by 21% to the use of RON98 fuel. You are completely over-egging the marginal benefits of a slightly higher compression burn which is offset by higher octane fuel being slightly less calorific (this is why most cars aren't set up to run RON98 - there are no real mpg gains).
If using RON98 fuel were the holy grail of better fuel economy and far better power output for the same amount of fuel in, all the cars would be running on RON98, you'd effectively be getting a free remap. The R and TCR would have better economy figures than the GTI Performance if geared with the same ratios, and CO2 levels would be lower as derived from the WLTP test cycle.
Those GTI performance 245ps would be quoted as 245/295ps depending on fuel used. They're not
Unlike diesel, petrol (whether RON95 or RON98) evaporates easily within the cylinder, dispersing and mixing evenly with the air, That air/fuel mix ignites easily under spark for a complete burn, whether that be RON95 fuel:air mix compressed 10.5:1 or RON99 fuel:air mix compressed 12:1. The alkane hydrocarbon chains (C6 to C10 Allan's, average C8 i.e. Octane) in either petrol variant are the same, but in RON98, a small amount of them are replaced with compounds that are much less volatile (like ethanol). They absorb the extra heat from the slightly higher compression to prevent preignition under the higher temp and pressure - those hydrocarbon chains making up the bulk of the chemical energy in the fuel are no more energetic. Combustion of RON95 under RON95 engine parameters or RON98 under RON98 both lead to a clean and complete burn due to how easily those air:fuel mixes combust. If that wasn't the case, those RON95 optimised cars would need bigger GPFs and perhaps those set up for RON98 wouldn't need one at all. We all know that isn't the case - my 2015 Golf R running solely on RON99 fuel had very sooty tailpipes.
This isn't the case with diesel. With a higher average molecular weight and stronger bonds, you need a hell of a lot more heat and pressure to combust that larger average molecule. The thermal expansion of the excess air under much higher temperature and pressure contributes a lot to diesel mpg - diesel is only 8% more energy dense than petrol, yet yields 30-50% more kinetic energy.
So back to the timing/antiknock issue.
In a RON95 optimised car, timing advance only goes so far, far enough to ensure it is advanced enough not to allow preignition of RON95 fuel and no further. There are no tangible advantages for the car to advance timing to allow RON99 to get to the verge of preignition.
The RON98 optimised engines need the capability to run RON95 under RON95 optimised conditions to avoid preignition, so they have a wider range of timing adjustment to suit RON95 and RON98 in the EU. The opposite is not true. You don't need to advance timing to combust RON98 under RON95 conditions, so no harm done.
The cars set up for RON99 have engine component differences to cope with the slightly higher temperatures and pressure -stiffer piston rods, higher level of silicon in cylinder heads for better heat resistance harder, harder piston crowns and valves etc. If VW had engineered their RON95 optimised engines to run under RON98 conditions when fuelled with RON98, they'd all have more resilient components as you see on the higher output engines. They don't, and so VW don't give their RON95 optimised engines the ability to run as a RON98 optimised engine with RON98 fuel.
RON98 optimisation is for higher output variants of engines to get a higher level of fuelling and achieve their higher output without preignition - nothing more than that.
RON95 optimised cars are not built for the higher temp and pressure that RON98 optimised cars run at, so they are not set up to reoptimise themselves for RON98 fuel if they are supplied it.
-
I completely get what you're saying, but it's as much about the chemistry of combustion as the engineering of the car.
There's no way you can seriously attribute your 1.4 Golf apparently overperforming by 21% to the use of RON98 fuel. You are completely over-egging the marginal benefits of a slightly higher compression burn which is offset by higher octane fuel being slightly less calorific (this is why most cars aren't set up to run RON98 - there are no real mpg gains).
If using RON98 fuel were the holy grail of better fuel economy and far better power output for the same amount of fuel in, all the cars would be running on RON98, you'd effectively be getting a free remap. The R and TCR would have better economy figures than the GTI Performance if geared with the same ratios, and CO2 levels would be lower as derived from the WLTP test cycle.
Those GTI performance 245ps would be quoted as 245/295ps depending on fuel used. They're not
Unlike diesel, petrol (whether RON95 or RON98) evaporates easily within the cylinder, dispersing and mixing evenly with the air, That air/fuel mix ignites easily under spark for a complete burn, whether that be RON95 fuel:air mix compressed 10.5:1 or RON99 fuel:air mix compressed 12:1. The alkane hydrocarbon chains (C6 to C10 Allan's, average C8 i.e. Octane) in either petrol variant are the same, but in RON98, a small amount of them are replaced with compounds that are much less volatile (like ethanol). They absorb the extra heat from the slightly higher compression to prevent preignition under the higher temp and pressure - those hydrocarbon chains making up the bulk of the chemical energy in the fuel are no more energetic. Combustion of RON95 under RON95 engine parameters or RON98 under RON98 both lead to a clean and complete burn due to how easily those air:fuel mixes combust. If that wasn't the case, those RON95 optimised cars would need bigger GPFs and perhaps those set up for RON98 wouldn't need one at all. We all know that isn't the case - my 2015 Golf R running solely on RON99 fuel had very sooty tailpipes.
This isn't the case with diesel. With a higher average molecular weight and stronger bonds, you need a hell of a lot more heat and pressure to combust that larger average molecule. The thermal expansion of the excess air under much higher temperature and pressure contributes a lot to diesel mpg - diesel is only 8% more energy dense than petrol, yet yields 30-50% more kinetic energy.
So back to the timing/antiknock issue.
In a RON95 optimised car, timing advance only goes so far, far enough to ensure it is advanced enough not to allow preignition of RON95 fuel and no further. There are no tangible advantages for the car to advance timing to allow RON99 to get to the verge of preignition.
The RON98 optimised engines need the capability to run RON95 under RON95 optimised conditions to avoid preignition, so they have a wider range of timing adjustment to suit RON95 and RON98 in the EU. The opposite is not true. You don't need to advance timing to combust RON98 under RON95 conditions, so no harm done.
The cars set up for RON99 have engine component differences to cope with the slightly higher temperatures and pressure -stiffer piston rods, higher level of silicon in cylinder heads for better heat resistance harder, harder piston crowns and valves etc. If VW had engineered their RON95 optimised engines to run under RON98 conditions when fuelled with RON98, they'd all have more resilient components as you see on the higher output engines. They don't, and so VW don't give their RON95 optimised engines the ability to run as a RON98 optimised engine with RON98 fuel.
RON98 optimisation is for higher output variants of engines to get a higher level of fuelling and achieve their higher output without preignition - nothing more than that.
RON95 optimised cars are not built for the higher temp and pressure that RON98 optimised cars run at, so they are not set up to reoptimise themselves for RON98 fuel if they are supplied it.
You say you "get what I'm saying...then go of at a tangent, then go back & reiterate in a different whey what I'm saying & then disagree with that I'm saying.... :huh:
Plenty of "95" RON marked MK7 Golfs like GTI have been dyno'd before remaps...many run on 98RON & many run on 95RON...& a general trend is that those on 98RON BEFORE remapping make MORE BHP than those just on 95RON...simple plain facts...98RON does make more BHP
If as you state that there is no benefit of running a 95RON marked car on 98RON & that it couldn't cope as it isn't built for it as the internal components are not as heat/strength resistant….then please explain the masses of cars & MK7 GTIs which are successfully running 98RON stage 1 maps (ECU end stops on data parameters opened up) with no other alterations to them & are making more BHP than your "98RON specific" R....& reliably...
VW will write the ECU data for both 95 & 98RON for a 95RON marked car......the car will make more use of 98RON under high load, high rpm conditions compared to using 95RON fuel...the ECU data parameters will allow this.....
UPTO the point that it causes problems with the engine due to high thermal load/damage & the safety end stops on the data intervene…….your 98RON "specific" as it has extra strengthening will have wider parameters written into the ECU as it can physically cope with the extra heat...…
Higher octane allows the ECU to use the full parameter range that is written in....
In simple diagrammatic terms to use as an example...say on a scale of 1 to 10....91RON fuel has ECU parameters in the range 1-3...95RON is 4-7...& 98RON is 8-10...….
The car with "91RON min" on the fuel flap will have values written unto it from 1-10 to cope will all the fuels knock & combustion responses in that engine...BUT the ECU will wind back/reduce from the "10" value in certain rpm & load conditions because the engine cannot physically cope with the heat etc...…
The car with "98RON" on the fuel flap will only have values from 8-10 written on it, but because the engine can physically cope with the heat etc there will be NO winding/reducing the values back as a safety net....
I don't know how much simpler I can make it for you to understand...
PS I never attributed the whole % gain in my car just to the fuel I stated that its just the drop in ITG filter & the fuel...but you state that it can't be the fuel...therefore the gain must be just the filter (according to you)...these filters don't make that much gain... & unfortunately these cars don't make a big % over book when run in on plain 95RON......so it is both the 98RON fuel & the air filter which makes the big % gain in bhp in my car.....
-
You say you "get what I'm saying...then go of at a tangent, then go back & reiterate in a different whey what I'm saying & then disagree with that I'm saying.... :huh:
Plenty of "95" RON marked MK7 Golfs like GTI have been dyno'd before remaps...many run on 98RON & many run on 95RON...& a general trend is that those on 98RON BEFORE remapping make MORE BHP than those just on 95RON...simple plain facts...98RON does make more BHP
If as you state that there is no benefit of running a 95RON marked car on 98RON & that it couldn't cope as it isn't built for it as the internal components are not as heat/strength resistant….then please explain the masses of cars & MK7 GTIs which are successfully running 98RON stage 1 maps (ECU end stops on data parameters opened up) with no other alterations to them & are making more BHP than your "98RON specific" R....& reliably...
VW will write the ECU data for both 95 & 98RON for a 95RON marked car......the car will make more use of 98RON under high load, high rpm conditions compared to using 95RON fuel...the ECU data parameters will allow this.....
UPTO the point that it causes problems with the engine due to high thermal load/damage & the safety end stops on the data intervene…….your 98RON "specific" as it has extra strengthening will have wider parameters written into the ECU as it can physically cope with the extra heat...…
Higher octane allows the ECU to use the full parameter range that is written in....
In simple diagrammatic terms to use as an example...say on a scale of 1 to 10....91RON fuel has ECU parameters in the range 1-3...95RON is 4-7...& 98RON is 8-10...….
The car with "91RON min" on the fuel flap will have values written unto it from 1-10 to cope will all the fuels knock & combustion responses in that engine...BUT the ECU will wind back/reduce from the "10" value in certain rpm & load conditions because the engine cannot physically cope with the heat etc...…
The car with "98RON" on the fuel flap will only have values from 8-10 written on it, but because the engine can physically cope with the heat etc there will be NO winding/reducing the values back as a safety net....
I don't know how much simpler I can make it for you to understand...
PS I never attributed the whole % gain in my car just to the fuel I stated that its just the drop in ITG filter & the fuel...but you state that it can't be the fuel...therefore the gain must be just the filter (according to you)...these filters don't make that much gain... & unfortunately these cars don't make a big % over book when run in on plain 95RON......so it is both the 98RON fuel & the air filter which makes the big % gain in bhp in my car.....
I know those filters make next to nowt - 1% if you're lucky - they're pretty pointless at stock power. The MAF ensures that stoichiometric air to fuel ratio is maintained and the stock filter is more than capable of supplying all the air needed, even at the end of its service life and partially blocked. So if you are attributing your 21% overperformance to fuel and filter and acknowledge that the filter is doing next to nowt, then the fuel must be responsible for almost all that gain.
There is no-one here in this forum with their RON95 optimised GTI PP who were putting in RON95 and are now putting in V-Power or Momentum99 and claiming TCR rivalling performance. At best they claim slightly smoother running and marginal gains that are small enough to be placebo effect
No way is your unmodified (save for the filter) 140ps 1.4 making 167ps because of your use of RON98/99. I doubt it's making more than 150-155ps, and that'll be due to a good run in and VW conservative stock figures.
The fact that 230ps GTIs are remapped to 300ps without failing immediately (apart from manual clutch failure) means nothing to your argument. VW maintain an engineering standard relative to stock power, to ensure it can cope, with some margin. If VW thought that their stock 230 PP could make 20% extra power simply by switching from RON95 to RON99, they'd ensure it had the same internals as the R and TCR. Otherwise, why do they make the R and TCR engine with hardier materials with better heat resistance? Why would they bin your warranty if they know you're remapping? Its because your stock car has been designed to run at stock levels (inclusive of some natural variance), and not at 20%+ of reported stock output.
An R puts out 22% more power than a 245 Performance because its using 20%+ more fuel at full tilt, not because the RON98 fuel is deriving 22% more power per volume than RON95.
Some simple questions for you to answer:
1. Why do 245 Performance GTI owners bother with a remap when (according to you) they can just put RON99 fuel in and one of your filters (which you admit does next to nowt) to get 295ps?
2. Why don't VW publish performance and economy figures for both fuel types if a RON95 optimised 245ps GTI can run like a TCR if you feed it RON99?
3. Why would anyone buy a 290ps TCR, running RON99 when they could buy a 245 performance and fill it with RON99 instead of RON95 to get 295ps?
4. Why aren't TCRs more economical than 245 GTIs on the WLTP testing cycle, with lower CO2 emissions to match, if you think that combustion of RON98/99 fuel is so much more efficient than combusting RON95 fuel (even accounting for slight weight differences between the 2)?
5. Why do VW. make the TCR/R/CSS engine variants with more robust and heat resistant internals, bigger intercoolers etc. if the 245 GTI is capable from stock of matching it for power if you give it RON99 fuel?
I'd like to know what your answers are to the above.
My answer to all of the above is that a 20% gain in power for using RON99 on a RON95 optimised car is bollocks and that a RON95 optimised car processes higher RON fuels the same way as it would RON95, with a timing setting to suit RON95. If there are any marginal gains, they will be because the timing is advanced to the top end of the RON95 range, with that RON99 fuel being combusted as an ideal RON95 fuel. Those gains will be tiny, like seeing slightly smoother running at the top end because the fuel is nowhere near the cusp of preignition when it is spark ignited, no meaningful bhp or mpg gains. Certainly nowhere near enough to justify the additional cost.
Your argument is based on the premise that your car would be running 140ps on RON95 fuel but is running 169ps/167bhp on RON99 and a largely superfluous filter.
You also assume that running under slightly higher temps/pressures as per a true RON98 optimised car is significantly more efficient. It isn't - it's a tiny step towards the way diesels operate under much higher temperature and pressure, a tiny step, whilst using fuel that is slightly less calorific than RON95.
-
I think I might go and get a job in the fuel industry after gaining all of this knowledge. This lockdown is affecting people in weird and wonderful ways :laugh:
-
I know those filters make next to nowt - 1% if you're lucky - they're pretty pointless at stock power. The MAF ensures that stoichiometric air to fuel ratio is maintained and the stock filter is more than capable of supplying all the air needed, even at the end of its service life and partially blocked. So if you are attributing your 21% overperformance to fuel and filter and acknowledge that the filter is doing next to nowt, then the fuel must be responsible for almost all that gain.
There is no-one here in this forum with their RON95 optimised GTI PP who were putting in RON95 and are now putting in V-Power or Momentum99 and claiming TCR rivalling performance. At best they claim slightly smoother running and marginal gains that are small enough to be placebo effect
No way is your unmodified (save for the filter) 140ps 1.4 making 167ps because of your use of RON98/99. I doubt it's making more than 150-155ps, and that'll be due to a good run in and VW conservative stock figures.
The fact that 230ps GTIs are remapped to 300ps without failing immediately (apart from manual clutch failure) means nothing to your argument. VW maintain an engineering standard relative to stock power, to ensure it can cope, with some margin. If VW thought that their stock 230 PP could make 20% extra power simply by switching from RON95 to RON99, they'd ensure it had the same internals as the R and TCR. Otherwise, why do they make the R and TCR engine with hardier materials with better heat resistance? Why would they bin your warranty if they know you're remapping? Its because your stock car has been designed to run at stock levels (inclusive of some natural variance), and not at 20%+ of reported stock output.
An R puts out 22% more power than a 245 Performance because its using 20%+ more fuel at full tilt, not because the RON98 fuel is deriving 22% more power per volume than RON95.
Some simple questions for you to answer:
1. Why do 245 Performance GTI owners bother with a remap when (according to you) they can just put RON99 fuel in and one of your filters (which you admit does next to nowt) to get 295ps?
2. Why don't VW publish performance and economy figures for both fuel types if a RON95 optimised 245ps GTI can run like a TCR if you feed it RON99?
3. Why would anyone buy a 290ps TCR, running RON99 when they could buy a 245 performance and fill it with RON99 instead of RON95 to get 295ps?
4. Why aren't TCRs more economical than 245 GTIs on the WLTP testing cycle, with lower CO2 emissions to match, if you think that combustion of RON98/99 fuel is so much more efficient than combusting RON95 fuel (even accounting for slight weight differences between the 2)?
5. Why do VW. make the TCR/R/CSS engine variants with more robust and heat resistant internals, bigger intercoolers etc. if the 245 GTI is capable from stock of matching it for power if you give it RON99 fuel?
I'd like to know what your answers are to the above.
My answer to all of the above is that a 20% gain in power for using RON99 on a RON95 optimised car is bollocks and that a RON95 optimised car processes higher RON fuels the same way as it would RON95, with a timing setting to suit RON95. If there are any marginal gains, they will be because the timing is advanced to the top end of the RON95 range, with that RON99 fuel being combusted as an ideal RON95 fuel. Those gains will be tiny, like seeing slightly smoother running at the top end because the fuel is nowhere near the cusp of preignition when it is spark ignited, no meaningful bhp or mpg gains. Certainly nowhere near enough to justify the additional cost.
Your argument is based on the premise that your car would be running 140ps on RON95 fuel but is running 169ps/167bhp on RON99 and a largely superfluous filter.
You also assume that running under slightly higher temps/pressures as per a true RON98 optimised car is significantly more efficient. It isn't - it's a tiny step towards the way diesels operate under much higher temperature and pressure, a tiny step, whilst using fuel that is slightly less calorific than RON95.
Please make up your mind re my car, is it the 98RON fuel, the air filter or like that from the factory??..
You forget I stated that dyno runs of these engines (in for remaps) have shown that from factory on 98RON they make more than 95RON cars…BEFORE remapping….& that I am still making slightly more due to air filter & possibly running in method etc…
Now you are also stating that quote:- “No way is your unmodified (save for the filter) 140ps 1.4 making 167ps because of your use of RON98/99. I doubt it's making more than 150-155ps, and that'll be due to a good run in and VW conservative stock figures.”
Yet I explained to you how to do the data read outs from the engine ECU as you wanted to know how it was possible…as you did not know this was possible.
Your whole arguments re the 2lt engines in the GTI & R….Quote:- “”An R puts out 22% more power than a 245 Performance because its using 20%+ more fuel at full tilt, not because the RON98 fuel is deriving 22% more power per volume than RON95””.
The main reason it makes more power….R & Clubsport are fitted with a bigger IS38 turbo….which is why it also has the additional lower front coolers….the other 2lt engines just have the smaller IS20 turbo….without the additional lower bumper mount coolers…
The reasons that VW make & over engineer is to provide an engine which can cope with +40C outside heat with air-con at max & a person flooring it up a steep road & the heat soaking it..again & again…..right down to -40C cold & idling basically to cope with world wide environmental demands….go research how they test the cars…..
You are changing your tack, ignoring actual facts about the engines, & are getting totally confused….I can’t explain anything any clearer to you...
-
^ No confusion at all.
You claim that your stock (save for the air filter) 1.4 Golf is putting out 21% more than stock because you've done some indirect calculations to get to that figure.
You say your car is making 21% over stock because you use RON98 fuel.
You say that a Golf R makes 22% more because it has a bigger (IS38) turbo than the performance GTI (IS20) and bigger intakes. They certainly help, but we know that a remapped GTI can make 300ps with stock IS20 (which will be working harder than it was before) and no intake mods.
So your car can uniquely make 21% over book output by dropping in a superfluous air filter, but being otherwise stock hardware and feeding it RON98, yet the same doesn't apply for the Golf GTI 230/245 because it doesn't have the R/TCR's additional/improved hardware?
The ECU has a map for the car that governs all kinds of parameters with an end goal of achieving it's stated output or thereabouts as economically and cleanly as possible. A RON95 optimised car doesn't have a +20% power function for when it's being fed RON98. If it is meant to make 140ps, it'll make 140ps or thereabouts because the ECU won't allow massive overfuelling to make that extra 20% just because you're using RON98 in a RON95 optimised car.
It would need a completely different WLTP test economy set of figures and CO2 rating when running RON98 in the way you imagine it happens.
Who wouldn't buy RON98 fuel at 10% premium over RON95 to gain 20% more power? You'll put the remap companies out of business.
It's clear we're not going to come to any agreement, so you carry on thinking your car is really running 21% over book because you're running it with a fuel it is not optimised for, and I'll keep thinking otherwise because I believe you don't get 20% more power than stock without remapping and consuming 20%+ more fuel in the process.
For everyone else without a TCR/R/CS/CSS, forget paying for remaps, just fill up on Momentum 99! :grin:
I used to fill my R exclusively with Momentum 99 until my local Costco got a filling station and I then switched to their own RON99 fuel which was just as good.
When we got our first Polo GTI (2.0TSI EA888 3b, 200ps 320Nm, without GPF), I started filling it with the Costco RON99 stuff, for the first 5 tanks/1400 miles. I switched to Costco's RON95 and there was no difference in performance, my mpg improved a little on RON95, not enough to be conclusive - 1mpg, could be natural variation accounting for that. No gains in using RON99 with that engine.at all. It's basically a detuned Golf GTI engine with IS20 turbo, retains port injection and has the Audi valve lift tech on the inlet side to facilitate a high effective compression ratio with a very lean mix under low loads for better low load fuel economy (Budack cycle).
-
You claim that your stock (save for the air filter) 1.4 Golf is putting out 21% more than stock because you've done some indirect calculations to get to that figure.
You say your car is making 21% over stock because you use RON98 fuel.
I've just quoted the first few bits from your long post.
By totally mis-quoting what I have posted you have yet again proved that you are not reading or understanding anything that I post.
I'm out, my time is too important to waste on you.