RB5RLP

Hi All
I bought my STI just over a week ago and have been told that it has been mapped for Optimax , its a 1998 STI S plate runing 320 BHP with full decat , can I use SUL 98 Ron or should I stick to 99Ron and above ????? I have been using V power from shell but thought I would ask the question due to the recent petrol price reductions and the 3 mile trek to fill up at shell ..... some feedback would be appreciated ... the car was mapped at Powerstation.

Russ

MaDaSS

Stick to the good stuff. My nearest shell is 7 miles away and i dont see that as a problem.
The optimax was good, so the v-power should be better what with the higher ron rating. Its also all the additive ****e they put in it as well.
Loads of ppl swear by Tesco 99 ron, but i am in Notts and that aint up here yet.
Tbh, stick to Shell.

RB5RLP

But can I use SUL 98 Ron in the car or not ???

rmtypeR

Old Optimax was suppposed to be 98.6 RON so I doubt the 0.6 drop will do any harm! Although where can you get the 98 RON fuel you mention - I thought that other than Optimax/V-Power and Tescos, all other fuel was 97 or below? Correct me if I'm wrong (I may well be!) but I thought that one of the reasons for the high octane rating of Optimax was that it had octane booster added. If that's the case then over time these will fade - e.g. if the fuel in your tank is a couple of weeks old it's probably lower octane than it was when you filled up.

I had my car mapped with Tescos 99 and my mapper said there shouldn't be any problem running it on 98 (in Germany that is).

RB5RLP

Not having used SUL for such a long time, is SUL rated at 98 Ron then ???

Beastie

iTrader: (2)

no, SUL is rated at 97 RON

RB5RLP

Cheers Beastie

Would I be safe to use 97 Ron if the car was mapped on 98 Ron ???? is there a big difference ????

New_scooby_04

iTrader: (4)

Hi Russ,

Simple answer: you should use fuel with an RON equivalent to, or greater than, the one your car was mapped for. So really, it's V power or Tesco's 9RON for you. Std SUL is 97 RON so not really adequate, depending on how your car was mapped (and you should check this with your mapper), you'd probably be ok with 97 RON as the ECU would pull back the ignition to compensate, the consequence of this would be the car running at reduced power. Using a petrol with higher RON might not result in much/any improvement in performance over what your car was mapped for, but gives you a greater safety margin against detonation, if I understand it correctly.

Ns04

RB5RLP

Cheers Bud off to Shell we go

New_scooby_04

iTrader: (4)

Optimax was great and I've no reason to doubt V power will be any different. Avoid BP ultimate, several mappers have reported that Scoobs just arent happy on this petrol!

Ns04

Trap2Terrorist

iTrader: (3)

I had mine mapped by Powerstation orginally on Texaco HighOcatne (97 RON) but following a full decat had it mapped again, this time running on Tesco99.

I asked them whether it would be ok to run it on 97 RON if needed and was advised not to unless necessary and then only put in a small amount of fuel.

Even though the ECU can retard the ignition advance to try and compenate for the lower octane fuel, it won't be able to do enough and it could cause problems.

RB5RLP

Thanks for the advice chaps, just filled up with V power sticking with this fuel will let you know how I get on...

Russ