GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Golf mk7 GTD/TDI => Topic started by: tuscan on 11 July 2013, 10:54
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Hi Ive never owned a relatively high performance diesel before, I've always had petrol. so was just wondering if you guys will be using standard diesel or something like V Power diesel?
Does it make any difference?
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This might best go on the brand new TDI section?
http://www.golfgtiforum.co.uk/index.php?board=128.0
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Mods - could we move to the child board at top of page :wink:
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As long as you avoid Morrisons diesel you should be fine with any. Some people use Shell V power only or bp ultimate only and say its quieter etc. If your using shell from new then in theory your new gtd should remain cleaner.
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As long as you avoid Morrisons diesel you should be fine with any.
Straight up - what's wrong with Morrisons diesel? Isn't all petrol/diesel regulated to a very high standard in this country?
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It's got a higher percentage of bio-diesel in it than all the others. Last time I checked the pump it was 7%.
It doesn't really matter as most OEM's stipulate a seals package on their fuel systems up to 10% capable, and warranty them for 5%. It's personal preference if you choose to use it. Some feel it helps, others feel it hinders.
It's all the same from the refinery, it just has different additives added to it prior to arriving at the forecourt.
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It's got a higher percentage of bio-diesel in it than all the others. Last time I checked the pump it was 7%.
It doesn't really matter as most OEM's stipulate a seals package on their fuel systems up to 10% capable, and warranty them for 5%. It's personal preference if you choose to use it. Some feel it helps, others feel it hinders.
It's all the same from the refinery, it just has different additives added to it prior to arriving at the forecourt.
I get ya. It's the additives they add post production that make it an inferior product at the pump.
Call me naive but why would they be adding additional additives to their diesel if it makes it worse? Furthermore adding additional additives is an extra, post production expense yet they still manage to under cut the big boys (slightly).
Still not clear on this :undecided:
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Morrisons use more Bio diesel stuff than any other petrol stations (apparently). VW's dont run too well on bio diesel and the tuning company next to where I live said he'd had a quite a few VW's in that had been using morrisons diesel and it had caused issues ie lumpy running, poor mpg's.
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Morrisons use more Bio diesel stuff than any other petrol stations (apparently). VW's dont run too well on bio diesel and the tuning company next to where I live said he'd had a quite a few VW's in that had been using morrisons diesel and it had caused issues ie lumpy running, poor mpg's.
Biodiesel has a different combustion profile that screws with DPF regens, VAG TDI technology does not like biofuels.
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Ok, lets get rid of some smoke and mirrors. It's the FUEL SYSTEM that issues are caused through. This is normally to do with progressively higher combustion pressures that are being used to get diesels through tighter and tighter emissions legislations. EURO 6 being most recent, at which point injection systems are heading towards 6000BAR injection pressure. PD engines (early years up to 05) were ok with lower concentrations, higher spec ones mk5 140pd etc didn't like it so much because of the below.
The Bio-diesel content of it corrodes the rubber components (Seals etc) in the high pressure side especially. Viton is the usual replacement as Nitrile just doesn't cut it. OEM's normally guarantee their fuel system to 10% biodiesel content, and it is the manufacturers choice what they warranty up to which is usually lower. I used to be employed by a tier 1 OEM diesel fuel system supplier hence how I know this.
It does have a different profile chemically, but whilst employed by them I never ONCE heard of it being an issue with the DPF. That's not to say it doesn't mess around with it, but generally it presents as running rough or missing (cold start predominantly due to waxing temp).
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Ok, lets get rid of some smoke and mirrors. It's the FUEL SYSTEM that issues are caused through. This is normally to do with progressively higher combustion pressures that are being used to get diesels through tighter and tighter emissions legislations. EURO 6 being most recent, at which point injection systems are heading towards 6000BAR injection pressure. PD engines (early years up to 05) were ok with lower concentrations, higher spec ones mk5 140pd etc didn't like it so much because of the below.
The Bio-diesel content of it corrodes the rubber components (Seals etc) in the high pressure side especially. Viton is the usual replacement as Nitrile just doesn't cut it. OEM's normally guarantee their fuel system to 10% biodiesel content, and it is the manufacturers choice what they warranty up to which is usually lower. I used to be employed by a tier 1 OEM diesel fuel system supplier hence how I know this.
It does have a different profile chemically, but whilst employed by them I never ONCE heard of it being an issue with the DPF. That's not to say it doesn't mess around with it, but generally it presents as running rough or missing (cold start predominantly due to waxing temp).
I agree with almost everything you said - biodiesel rots rubber and there are rubber components in the VAG system that VAG don't seem to want to get rid of, even though they could.
Also though, biodiesel has a higher auto-ignition point which poses no issues via normal engine ignition, but could cause issue with DPF regeneration when a forced regen is initiated with the attempted ignition of fuel in the exhaust/DPF system. Germany are big on biodiesel content, they are pushing for higher coontents - VAG TDIs have to be a bit selective on where they fill up in Germany because of this.
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I recently got 73mpg on morrisons diesel in my gtd.
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I recently got 73mpg on morrisons diesel in my gtd.
"more reasons to shop at morissons". My TDIs have all preferred Shell and BP to anything else with noticeable economy increases.
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I recently got 73mpg on morrisons diesel in my gtd.
were you driving down hill at the time? :grin: :grin:
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I recently got 73mpg on morrisons diesel in my gtd.
were you driving down hill at the time? :grin: :grin:
He was driving down hill..With the engine actually turned off! :grin:
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I still don't fully understand why Morrisons add bio-diesel additive to their product? Surely that's an additional cost to them post production.
Their basic, refined diesel will be bought wholesale on the open markets and then they add additives to make the product sh*te? Doesn't make sense.
Why would Morrisons want to alienate Volkswagen TDI drivers (or any high psi diesels cars)? VW are one of the biggest car manufactures in the world, it would be business suicide to turn your back on millions of customers.
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Thing is how many people actually know about the possible damage it can cause.....99% of the public live in ignorance and most owners have the car for just the 3 years and change it again so have no real interest in what fuel they are putting in
Its the 2nd hand market where it will have the biggest impact as those people will be footing the bill
I always avoid any form of supermarket fuel. My car feels noticeably different and produces more smoke on the stuff
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The fuel isn't actually shyte. It depends on the demographic you aim for. Plus it can (car dependant) help you squeeze a few more MPG out, which is nice for Fleet car drivers (large portion of business for Morrisons et al no doubt)
Most cars on todays roads are an average age of at least ~7 years old? (guesstimate) in which case most will never know of or see any issue with filling up with diesel bio content or not.
Lets not forget, what is THE driving factor in where people fill up their cars now-a-days? Price. Nothing else. It's the reason the VOSA people have been cracking down on fuel testing by the side of the road as well, as Red agri diesel is getting used more and more.
I will freely admit to hitting up morrisons with the passat if the price is right but I don't have as much to worry about as mine is a 130pd so not as many injector issues. I do however flush through with a tank or two of shell every so often and a millers additive to help keep things healthy (well as healthy as a big lump of pig iron can be).
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Ummm...confused :huh: are you saying no to Morrisons?
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Ummm...confused :huh: are you saying no to Morrisons?
I say NO to all supermaket fuels :grin:
I refuse to tarnish my fuel system with anything from the supermarkets; thats just my opinion and going by how my past two cars have responded (or not) to the stuff :smiley:
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Ummm...confused :huh: are you saying no to Morrisons?
I think he (sick) is definitely saying no to Morrisons diesel for modern, high pressure TDIs.
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Ummm...confused :huh: are you saying no to Morrisons?
I think he (sick) is definitely saying no to Morrisons diesel for modern, high pressure TDIs.
Thank you H5O, Morrisons is my normal stop so really helpful. Tesco's would be my next stop...is that ok?
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I would stay away with 2008 systems onwards.
Asda is basically a no no.
Tesco is not the worst of the bunch by a long way (typically just bog standard diesel)
Sainsbury's I've used a couple of times, but more out of need than want.
I've fortunately got a very good priced Shell garage at my work place now so just go there.
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I would stay away with 2008 systems onwards.
Asda is basically a no no.
Tesco is not the worst of the bunch by a long way (typically just bog standard diesel)
Sainsbury's I've used a couple of times, but more out of need than want.
I've fortunately got a very good priced Shell garage at my work place now so just go there.
Ok Thanks, I will bow to your greater knowledge, even though my Shell garage is 3-4p per litre dearer (800 miles a week on average)
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I would stay away with 2008 systems onwards.
Asda is basically a no no.
Tesco is not the worst of the bunch by a long way (typically just bog standard diesel)
Sainsbury's I've used a couple of times, but more out of need than want.
I've fortunately got a very good priced Shell garage at my work place now so just go there.
Ok Thanks, I will bow to your greater knowledge, even though my Shell garage is 3-4p per litre dearer (800 miles a week on average)
However..... as others on here have outlined, if you only plan in keeping the car 3 to 4 years put what the hell you like in it :wink: It'll be somebody else's problem further down the line (if ever a problem does occur).
If you do 800 miles per week 3-4p per litre extra over the year is quite a of extra dosh to shell out. I'm a tight arse and fill up at ASDA whenever possible (petrol) and I've never felt any difference in performance whatsoever (compared to BP, Shell et al).
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If that 3-4p a litre premium yields extra mpg then it will be money well spent. 2 extra mpg and you're quids in. Might need to try it and see if you experience a significant increase in mpg using the premium stuff.
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If that 3-4p a litre premium yields extra mpg then it will be money well spent. 2 extra mpg and you're quids in. Might need to try it and see if you experience a significant increase in mpg using the premium stuff.
I hate to be picky but there are so many environmental factors which could influence mpg +/- outcome (hot day, cold day, heavy traffic, smooth traffic, strong headwinds, tailwind, using the air con etc, etc.) It would be nigh on impossible to conclusively proof increased fuel economy from the premium product under average driving conditions (IMHO).
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If that 3-4p a litre premium yields extra mpg then it will be money well spent. 2 extra mpg and you're quids in. Might need to try it and see if you experience a significant increase in mpg using the premium stuff.
I hate to be picky but there are so many environmental factors which could influence mpg +/- outcome (hot day, cold day, heavy traffic, smooth traffic, strong headwinds, tailwind, adverse weather etc, etc.) It would be nigh on impossible to conclusively proof increased fuel economy from the premium product under average driving conditions (IMHO).
I always got better MPG from forecourt fuel compared to supermarket fuel :nerd: hence why i stopped using supermarket fuel years ago!!
To be clear im only talking about the standard forecourt fuel and not the premium diesel that is also on offer; never really found much improvement and stations selling premium diesel are few and far between in the valleys :sad:
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800 miles per week at 4p cheaper is £125 per year, assuming an average 50mpg. So to break even you need to save £125 at £1.4 = 90 litres. You are using 60L per week so you need 1.5 weeks free out of 52 = 3% or 51.5mpg.
3% sounds like a big gain, but not a huge one. :undecided:
However, http://www.petrolprices.com puts the average premium diesel at 10p, or 7%, more expensive so you'll have to shop around and be sure you really are only paying 4p more at most than what you could have paid.
Semi off topic, my GTI will probably be getting Tesco 99. I've heard that gives the best improvements in power and efficiency when coupled to a variable cam time capable engine...
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its Morrison's diesel I'm talking about avoiding. petrol wasn't mentioned by the original poster. put whatever petrol you like in but if your going down gtd route don't use Morrison's diesel. I've used sainsburys diesel for years and never had any issues but I avoid Morrison's, asda and tesco for my diesel.
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You'd need a few tankfuls of V-power to drive it to the point you'd be confident it makes a mpg difference, if it does at all.
If you look at Shell's own website, V-power Nitro in either Petrol oor Diesel variants is marketed at keeping your engine clean, which leads to efficiency gains, rather than making out that it's more potent and gains in mpg will be seen directly. Fuel tech across the board has come on so much in the past 10 years, even basic diesel is very clean, so are there any significant build-ups in the engine of a recent car for V-power to be cleaning?
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Semi off topic, my GTI will probably be getting Tesco 99. I've heard that gives the best improvements in power and efficiency when coupled to a variable cam time capable engine...
Bill, what's the GTI set up for? If it's set up for RON95 you might not see appreciable gains in using RON 98/99. If it's set up for 98/99 but capable of running 95 then you'll see those gains.
I was under the impression from previous brochures that 2.0TSI on MK5 and MK6 were set up for RON98 but were capable of running RON95 when higher octane fuels weren't available. On the current brochure it would seem that recommended fuel for GTI is RON95, with ability to use higher octane fuel. Variable timing allows it to use both, but preference of the engine seems to be an unknown at this stage. Anyone tried both for a few tanks each and conveyed the results yet?
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I really don't know what I'm talking about...
However, I read that the variable cam timing and height allows the engine to adjust to the higher octane and use less fuel giving you improved mpg. The test I read about showed best gains with Tesco 99 and specifically said you need the variable cams to take advantage of it.
Like I say this is not my area of expertise.
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
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I have 57k on the clock now no problems as such and it used to be run on Shell fuel as I thought it was better and it might be I am no expert, but when it became 3p more a litre I figured that's not worth it. (1000 miles a week). 73mpg was on my normal 28 mile trip to work in the morning, I think I have perfected the route really. Its a mix of 30/40 to 70 for a few miles then the remaining journey at 50/40/30. I have to admit it probably very hard to find any diesel that's not 5% bio these days and the majority are probably all 7% by now. They certainly don't advertise it that well. Most it states a particular BS standard on the pump somewhere.
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
Nice. Unless you change the compression ratio you'll not notice a difference with higher octane. So if I've got this right the variable cam timing will adjust the compression ratio and the variable cam height will adjust the mixture (guessing that second part?) so the ECU can make use of the higher octane to reduce the amount of fuel needed and increase the mpg? Not sure how the ECU will know how to do this though. Anyone confirm/deny this?
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
Fascinating video that p3asa :nerd: I learnt a lot watching it and now clearly understand what the octane rating means. I also learnt something about compression ratios too.
Basically if your engine is rated to 95 RON then there is absolutely now reason to put anything higher into your tank. You might as well burn money.
Cheers matey :smiley:
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Knock sensors, cam postion sensors, sensors, sensors.... etc.
Basically it detects pre ignition and will either retard/advance the timing on the engine so that it can stop damage from the fuel pre ignition. So valves will either open sooner (retard) or later (advance) thus mixture has more / less time to be burnt fully. The other thing is that it will meter the fuel required as well so higher octane = more bang per mg, so less will be injected into the cylinder on each compression stroke.
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Knock sensors, cam postion sensors, sensors, sensors.... etc.
Basically it detects pre ignition and will either retard/advance the timing on the engine so that it can stop damage from the fuel pre ignition. So valves will either open sooner (retard) or later (advance) thus mixture has more / less time to be burnt fully. The other thing is that it will meter the fuel required as well so higher octane = more bang per mg, so less will be injected into the cylinder on each compression stroke.
Cheers AG!
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
Nice. Unless you change the compression ratio you'll not notice a difference with higher octane. So if I've got this right the variable cam timing will adjust the compression ratio and the variable cam height will adjust the mixture (guessing that second part?) so the ECU can make use of the higher octane to reduce the amount of fuel needed and increase the mpg? Not sure how the ECU will know how to do this though. Anyone confirm/deny this?
Variable valve timing has nothing to do with compression ratio. Valve timing is when the valves open in relation to the piston position, Compression ratio is the difference between the volume of the cylinder at bottom dead centre compared to top dead centre. They will not effect each other.
I always use Morrison's diesel and never have a problem with it. If you think there is a difference you are kidding yourself.
Save some money and buy the cheapest fuel it all comes from the same place.
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
Nice. Unless you change the compression ratio you'll not notice a difference with higher octane. So if I've got this right the variable cam timing will adjust the compression ratio and the variable cam height will adjust the mixture (guessing that second part?) so the ECU can make use of the higher octane to reduce the amount of fuel needed and increase the mpg? Not sure how the ECU will know how to do this though. Anyone confirm/deny this?
Variable valve timing has nothing to do with compression ratio. Valve timing is when the valves open in relation to the piston position, Compression ratio is the difference between the volume of the cylinder at bottom dead centre compared to top dead centre. They will not effect each other.
I always use Morrison's diesel and never have a problem with it. If you think there is a difference you are kidding yourself.
Save some money and buy the cheapest fuel it all comes from the same place.
Does the spark not come later in VVT then?
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good video to explain octane http://www.youtube.com/watch?v=D9nhXNarFdg
Nice. Unless you change the compression ratio you'll not notice a difference with higher octane. So if I've got this right the variable cam timing will adjust the compression ratio and the variable cam height will adjust the mixture (guessing that second part?) so the ECU can make use of the higher octane to reduce the amount of fuel needed and increase the mpg? Not sure how the ECU will know how to do this though. Anyone confirm/deny this?
Variable valve timing has nothing to do with compression ratio. Valve timing is when the valves open in relation to the piston position, Compression ratio is the difference between the volume of the cylinder at bottom dead centre compared to top dead centre. They will not effect each other.
I always use Morrison's diesel and never have a problem with it. If you think there is a difference you are kidding yourself.
Save some money and buy the cheapest fuel it all comes from the same place.
Does the spark not come later in VVT then?
Erm, we are talking Diesel engines. There is no spark. the fuel combusts when it is injected into the cylinder under extreme pressure.
You are thinking about petrol engines. The timing of the spark is unrelated to the valve timing.
Compression Ratio: The difference between the volume of the cylinder when the piston is at the bottom compared to at the top. (cannot be adjusted without changing the crankshaft or changing the bore of the cylinders)
Valve timing: When the valve opens in relation to the position of the piston. (Not really adjustable you can change the camshaft or slip a tooth on the cam belt, VVT engines do change the valve timing in operation.)
Ignition timing(petrol engines only): When the spark plug sparks in relation to the position of the piston. this can be adjusted by moving the Distributor (on old engines) or the ECU takes control on modern engines.
All of these things are unrelated but need to be working in unison for the engine to run like a dream.
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Compression Ratio: The difference between the volume of the cylinder when the piston is at the bottom compared to at the top. (cannot be adjusted without changing the crankshaft or changing the bore of the cylinders)
Not strictly true. SAAB I think it was had an engine in production that could actively change the CR on the fly. Not by a lot but still impressive.
Ignition timing(petrol engines only): When the spark plug sparks in relation to the position of the piston. this can be adjusted by moving the Distributor (on old engines) or the ECU takes control on modern engines.
There is still an ignition timing as such on a diesel, albeit through the use of an injector. It's pretty much a liquid spark plug (now there is an idea)
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Erm, we are talking Diesel engines.
sh!t my bad. I gotta stop reading via email as I keep thinking I'm looking at replies to different threads. I'll get out of the TDI section now! :embarrassed: