Benefits of running super

**MunkyA4** · 07-10-2008,07:49 PM

Hi all

Just a quick Q. What are the benefits of running super unleaded and are there any disadvantages. Can I use Tesco's 99 RON Super in my Audi?

Thanks

Stu

**SEMKY** · 07-10-2008,08:04 PM

I notice a significant improvement running mine on Shell VPower....smoother, quicker, better starting, etc etc....
and I hope its not all in my head!

**-M-** · 07-10-2008,08:12 PM

Originally Posted by SEMKY

I notice a significant improvement running mine on Shell VPower....smoother, quicker, better starting, etc etc....
and I hope its not all in my head!

I definately notice the difference using Shell Vpower in all cars I've driven, including my GTi, my mum's mondeo V6 and even my brothers 1.2 punto .

**Crasher** · 07-10-2008,08:16 PM

Depends on if the car is programed for it. Flip open the fuel cap and see what it says. If it says Octane min 98/95 then yes, running 99RON will be of benefit. Some say 95/98 which is a bit confusing. If it says 95/91then the benefits are not so clear cut, in theory it could actually lose you power but in reality probably will not. It always makes me laugh when I see slogans like “High octane fun” or something such like, implying that high octane fuel is faster burning or something. The higher the octane of the fuel, the slower the burn.
Having said that, my mother swears blind her little Olop 1.4 (min octane 95/91) drives far better and goes further on Sainsbury’s 97RON, my wife’s 89 Golf 2 GTI 8v (98 only) (modified to 1900, high lift cam etc) blew its head gasket due to her running it on 95 as it pinked slightly. After some “re-education” she now runs it on Tesco 99 but I have caught her running 95 if she can’t be bothered to fill up at the right pump, what do we do about these disobedient women? My Octavia VRS is a 98/95 car from new and I am running an APR 95RON remap but I still run it on Shell V Power 99 although I look away when filling it up, £75 the other day!

**Captain Answer** · 07-10-2008,08:27 PM

Originally Posted by Crasher

what do we do about these disobedient women?

Blacken her eyes

**Will22** · 07-10-2008,08:53 PM

Could some one tell me what I should be running in my 2001 (X) Audi A3 1.8T Quattro as the last 2 fill ups (only just bought car) i have been filling with 95RON?!?!?!? Please help!

**MunkyA4** · 07-10-2008,08:57 PM

Thanks for the pointers. My fuel filler says 95/98 so i think i'll go for some tesco 99 and see how it goes.

Crasher, does the fact it burns slower mean that it goes abit further per tank?

Cheers

**hongkongstuey** · 07-10-2008,09:06 PM

what about vpower diesel?

i didnt notice much difference in mine but i noticed a bit of smoke. stopped using it now, think it may be my egr clogging up, posted about changing my egr for an allard pipe but got no replies? surely someone has on here, will be taking the car apart next week to see how clogged it is.

**Crasher** · 07-10-2008,09:08 PM

Will22, look at the sticker and it will say either 98/95 or 95/98 so Super Plus (Super is 97RON) would help.

It burning more slowly doesn’t mean better consumption; we are talking milliseconds difference per cycle. What the slower burn does mean is that the fuel is less likely to ignite spontaneously or burn too fast and this allows the use of more boost (in a turbo application), higher compression and more ignition advance before the onset of the dreaded detonation/pre-ignition and no, I am not going into that one here, it would (and has) fill many books. Books on infernal (sic) combustion theory are actually an excellent cure for insomnia, I think the last two I read took me about a year to get through but it is a fascinating subject that still isn’t fully understood.

**scotty33** · 07-10-2008,09:57 PM

My 1990 Audi coupe 20v is mapped for 95/91. Same as most catalyst equipped VAG cars of the 90's. For the very reason Crasher outlined above, I did not bother to even try super + in my car (for over 2 years of ownership), I was sure it would not drive any better.
However, I was aware that when you are cruising, the ECU uses the knock sensors to reach the highest achievable ignition advance - under these conditions, more mpg would be possible with higher octane. I made this point on another forum, and for the sake of it, I filled up with v power just to see if mpg went up.
After a few miles I was very surprised to find the car felt faster and had better throttle response, so much so that I have continued to use super+ fuel when possible. As a bonus, the mpg are better as I thought they would be.
I can only guess that there is a higher proportion of Toluene in the fuel, this stuff releases more energy than petrol when combusted?

Toluene info: http://www.justfourrings.com/phpBB2/viewtopic.php?t=476