VW Golf R32 Forum banner

Octane rating

15K views 41 replies 29 participants last post by  TonkaToy  
#1 ·
Placebo or not? Can I run my car safely on 95 /98 RON without any issues?

Performance aside, is the running of R32 (MK5) affected by consuming basic fuel?
 
#2 ·
I have put 95 in mine before , gotta admit tho I didn't notice any difference !
Normally stick to 98 preferably v power !
 
#9 ·
JezzaR32 said:
Always run mine on high octane. Dont notice a difference but i like the thought of it. Also, if you think about it, its 2.50 extra a fill up for it. Dig deep my friend.... dig deep.
Living in the countryside has it's advantages, high octane fuel isn't one though!
Hardly any where sells it without going out of my way
 
#10 ·
vw says 95ron is fine in the mk5, but always try get her running on the good stuff (v-power as much as possible or tesco 99)
 
#12 ·
Yea I'm 12 miles each way from my nearest Shell :(
 
#16 ·
Sorry to dig this thread up again, but as I'm on the lookout for an R I'm doing a bit of research and couldn't help noticing people were using V-Power. I've always ran my P1 on V-Power due to the risk of det with lower octane fuels when the engine is under load, but I wouldn't have thought it was neccessary on a NA engine? Don't get me wrong, V-Power will burn better and cleaner than other fuels, and if you can find/afford it then fair enough, but is it really a requirement with the R's? I was quite looking forward to being able to drive somewhere using my sat nav rather than the Shell route planner lol :)
 
#17 ·
I've never really noticed any difference when I've put the higher octane stuff in the tank.

These days I only ever put in RON 95 in and everything is good with my 3.2. It just runs so smoothly.
 
#18 ·
I always use Tesco Momentum (99 Ron) because of the cleaner burn. I also put a large dollop of Redex in EVERY fill to enusre the upper cylinder is kept at optimum performance. However, I cant honestly say I've ever noticed any difference in performance or economy, it's just peace of mind. I do the same for my other car, a Porsche 997, and once again, it's purely for reassurance that I'm keeping the car in peak health.

Or am I just being anal wand wasting money??? :hmmmm2:
 
#19 ·
This has been covered before.

States to use 98 RON in the manual of the Mk4. With a sub note stating that 95 can be used, but with reduced power output.
 
#21 ·
I just avoid Tesco 99 now due to its additives.
Think it was awesomeMike who stated that on the rollers a couple of cars performed worse on it than standard.

V-Power all the way unless its a silly central London price as its only a few quid extra per tank
 
#22 ·
tdub said:
I just avoid Tesco 99 now due to its additives.
Think it was awesomeMike who stated that on the rollers a couple of cars performed worse on it than standard.
Cant say I've ever had problems with Tesco, and v-power normally commands a 7p premium over regular 95 octane Shell petrol, which is more expensive to start off with than Tesco anyway.

Indeed, I ran a Bentley Continental GT and an Aston Martin V8 Vantage on Tesco without any issues whatsoever and both the R32 and the Porsche are currently doing fine on it.

So, if Tesco has cleaning additives, am I wasting my time slinging Redex in there too? And who actually supplies with Tesco with fuel as they certainly have no refineries????
 
#23 · (Edited by Moderator)
Lots of 'advice' but does anyone actually understand what the different octane ratings mean? It actually just tells you how much compression the fuel will take without combusting (without a spark from the spark plug). This is called 'Knock'. The higher the octane rating the better the resistans to ignition due to compression. Therefore, the higher the compression ratio of the engine the higher the octane rating you need to use. The higher the compression ratio the bigger the bang (for that mass of air/fuel) and the more power you can produce. The R32 has a compression ratio of 11.3:1 (off the top of my head, so don't quote me) which is fairly high so would benifit from the higher octane fuel.
Tests have shown that the tescos 99 ron can 'break down' for want of a better word if it's left sitting for a long time. Technically it does contain 99% Octane (and only 1% Heptane). So should resist knock very well. Octane is a string of 8 hydrocarbons whille heptane is a string of 7 in case anyone is interested.

Personally, I use Tesco 99 as there is a garage close to my house and it's cheap. Or I use the total 97 stuff because I pass one on the way to work. However, most of the time I use LPG because it's 70p/l cheaper! It is also has a higher equivalent octane rating but it's not quite as simple as that.

I hope that was helpfull and didn't put everyone to sleep! :boring:
 
#24 ·
i do get more miles from 99 than 95

thats about the only difference

the only other time you will see a difference if the exact same car came along and you had 99 and the other had 95, they wont be leaving you

tesco momentum is just as good as v-power
 
#25 ·
I use tesco 99 which was advised by VW mechanic who did the REVO remap on my mk5. He has had r32s before and now a edition30 and he said that there is no difference between tesco and v power.

Makes no odds to me as shell and tesco are both within 1 mile of me - but tesco momentum has served me well.
 
#26 ·
I always ran my MK V R32 on V power, but the one time I did fill up with 95 ron stuff I can't say I noticed a diffrence. You could tell in my 1.8t MkIV Rocco R and TT RS.