Super or regular?

[FamilyDub]

MKVI boys... search the MKV thread for all the chat about 95 RON vs 98 RON and what brands are better, etc...

Here: http://www.golfgtiforum.co.uk/index.php?topic=58444.50

The MKV FSi is mapped to run on the higher octane stuff, but it will run on 95 RON, albeit with less power (as the reaction is less explosive) and using more fuel in the process, as the fuel is less efficient. 

I'm sure VW wouldn't revert to older technology, surely...?

[FroGTI]

OK try it yourself.

Put 98/99 RON in your GTI for a few months. Then try a tankful of 95 (don't mix with the 98/99 RON).

Wouldn't advise doing this the other way around as I'm fairly certain the VW FSI engines are designed for 98/99 (although they can run on 95 if needed).

You will notice a loss of performance and economy.

I have done this with a couple of VW FSI engined cars.
Even the wife  noticed the difference and I didn't tell her about the different petrol so no placebo effect here.

 

Lol, ok I promise to give it a try. Anyway, I'm such a nerd, I would probably put 150RON in my GTI if I thought it would give me an extra 2hp

[Rolfe]

So, some say performance benefits, and some say economy benefits.

My auto-nerd friend with whom I spoke about this some time ago actually recommended the 98 for long-term engine health.  He said he always used the most expensive petrol in his car (a Merc estate).  However, he commented that given how long my Peugeot had been running on 95, he doubted that I'd get any benefit from changing.

Since I haven't tried it, I don't know about performance benefits.  Seems to me that the Golf goes like a bat out of hell anyway....

Economy benefits can be so difficult to assess without long-term controlled trials.  I notice two factors that seem to make a marked difference.  One is the route I drive, and how I drive it, obvious really.  Longer journeys at a relatively modest speed (say when held to a 60 limit by traffic conditions) produce quite miraculous improvements.  Start trying to get past that traffic though, and see what happens!  The other is the temperature, which I haven't heard mentioned.  Over many years I've noticed a significant drop in MPG when the weather has been freezing, and a significant rise when there's a heatwave.

Between them, these variables mean that over the years I've had anything from only about 370 miles on a full tank, in freezing weather with a lot of very short journeys, to 500 miles - right now, lovely warm weather and longer journeys often at 60mph.  Would have been even more if I hadn't decided to show a few people a clean pair of heels once or twice last week.  (Interestingly, this has never varied with the age of the car - I'm getting the best petrol consumption I've ever had right now.)

Seems to me that colder or warmer weather has more of an effect than is often taken into account, and unless a trial is repeated several times in all weathers the results might be misleading.  A heatwave just happening to coincide with the change in petrol could fool anyone.  It would be interesting to see some official figures from trials controlled for these variables.

As far as my new Golf is concerned, I think I'll ask the dealer what the engine is designed to run on, and give it that.

Unless anyone knows different?

Rolfe.

[R32UK]

the new Gti does not need to run on 98ron like the mk5 gti used to. 95ron will be fine.

Elaborate please?

As others on here have stated before the petrol cap on the MK5 stated that 97Ron or higher should be used. This is no longer the case with the MK6 engine. The petrol cap now states 95Ron. of course higher can be used, but for what purpose??


might possibly give you a very slightly improved mpg, but at the extra cost there is only one winner

might give you and extra 10bhp, but in all honesty how often are you going to be at 6600rpm using all 210 horses?? 

If an engine is designed to run on it, then by all means use it. If your under the impression that spending more money on an already expensive machine is going to give you some thing better then your slightly deluded. imo of course


p.s. Should you feel the need to waste more money on your golf then pls PM me for my bank details.... I CAN/WILL help!

[R32UK]

Rolfe.. I can understand that short journeys in winter would use more fuel. However you are aware that cars are more efficient in winter due to the denser air??

Summer time means that on start up it doesnt need to run at increased fuel for as long a period as in winter. But performance does suffer as a result.

[Rolfe]

Rolfe.. I can understand that short journeys in winter would use more fuel. However you are aware that cars are more efficient in winter due to the denser air??

Summer time means that on start up it doesnt need to run at increased fuel for as long a period as in winter. But performance does suffer as a result.

That's very interesting.  So it's all down to the start-up?

I'm not noticing the difference so much now, with an 11-mile journey to work mostly cruising at 60, as I was in my previous job where I pretty much worked round the corner (about a mile, and yes I should have cycled more).  But I'm still getting my best fuel consumption in warm weather for all that.  I'm surprised that start-up should make so much difference, especially as the Peugeot has always been a one-turn-of-the-key car.

Rolfe.

[R32UK]

You will find that over longer journeys the start up doesnt make that much difference... but in winter the car will run on higher fuel (choke) for a slightly longer period. Where as in summer it will be up to full operating temp in little or no time at all.

Not sure about the rest of the guys on here but the decrease in performance on a warm summers day is very noticable.. in fact if I remember correctly there was a discussion about it over on the MK5 board not so long ago.

[neo66]

if some of you guys look in your fuel cap, it says min 95 ron. (ok, you can't get much lower than that really)
But you spend enuff money buying the car, I believe its worth giving it the good stuff!.
Problem I findis that I use V-power, and thats 5 miles down the road for me, the nearest is Texaco which is only 97 ron, aswell as BP, tho they still charge even more than the V-power!

[adw555]

always used Super unleaded in my 05 GTI. The aircon has never been switched off and the mpg average never dropped below 33/34 mpg....except when I tried ordinary unleaded for 2 weeks..it dropped down to 30/31 .....got used to paying more for the previous car..an impreza turbo....good news if the mk 6 doesnt need it though 

[AlanD]

Not read all of it but to clear things up you dont HAVE to use super, the car will run fine on 95RON petrol. The FSI engines are designed to run on the higher RON petrol. Dont bother with BP as its 97RON, my advice is to use either Shell or Tesco which are both 99RON.

Not sure about the rest of the guys on here but the decrease in performance on a warm summers day is very noticable.. in fact if I remember correctly there was a discussion about it over on the MK5 board not so long ago.

Correct, I have also noticed my tubby has just a tad less kick to it when its roasting outside

if some of you guys look in your fuel cap, it says min 95 ron. (ok, you can't get much lower than that really)

Really? My MK5 says to use to 98RON petrol, I can only imagine the MK6 will be the same?