deco c

just wondering if i would do any damage to my 99 jap import sti if i run it on 95 ron with octane booster as it is very hard to get higher ron fuel where i am or would the car be safe just on 95 on its own,i heard it wont do any damage just that the car wont perform 100%.....is this true?

WezGT555

Im no mechanic but I have been asking the same question as you for the past few weeks. To summ up what i have been told:

Jap import Sti's are designed to run on 100/102 octane. Anything less and you do run the risk of detonation & engine failure. This is more likely to happen when really giving the car some stick or at high speeds. It is recommeded to either get the car remapped for the type of fuel you are using, or failing that, use octane booster. Octane boost can damage your cat and some have told me it will shorten the life of your plugs.

Are you in Ireland by any chance? You can get the car remapped for 95 but I dont know of anyone who has done this so cant comment on practicality/performance. A company called torque developments in wicklow can carry out the job for €1200. But I do know that the remapping process is a fairly skilled job so I would definitely enquire about the experience of the mapper before getting it done.
A lot of sti's in the UK are remapped for shell optimax (98.6 octane).

As for the car not performing, it is true you will lose some bhp when running on a lower octane fuel than required, say 10% for 95.

Hope this helps!

Wes.

deco c

cheers wes,yes i am in ireland and its just getting harder to get high octane,texaco are really the only ones its 97 octane and lately they havent had any,im just afraid il damage my engine,if anyone else could shed light on the subject it would be much appriceated.cheers.

New_scooby_04

iTrader: (4)

It's not just a performance issue with JDMs, as Wez says, it's a serious engine issue. Wrong grade fuel = Bang....probably sooner rather than later. If you don't already have a knock link, get one ASAP! 95 and Octane booster would be better than 95 alone, but if I understand correctly, 98 and OB is better! A remap for the kind of fuel you have easy access to is a very good idea. In the interim at least the Knock link will tell you if your engine is detting and give you the chance to back off.

Regards,

NS04

Kevin Groat

Deco, I've run my V3 STi on 95 ron nul for the last 40k miles/6 years. My nearest sul is a 14 hour ferry journey away Car is decatted and runs a K&N other than that it's standard. Regular visitor to the redline, maintained myself and I've had no problems. Also bought a GTB last year and ran that through the winter on nul - no problem either. Now, I wouldn't advise you to run on nul but in my case it was either run on nul or don't buy an STi - worth a gamble I thought

flamesuit on awaiting bolt of lightning, typing the above has probably triggered an alarm and flashing light in the technical forum

Stiver3

It is a real problem... I have an Sti VerIII and always put in Optimax and then Miller octane booster (2 octance point raise). This overall is 100ron fuel.... as has been said anything less when giving it the gun particularly can cause serious damage over time.


If you can only get 95 ron fuel.. best to use CVL booster or NF as this raises octnace by 5-6 points... but is costly....maybe evey other tank...?

Best way ius a remap if you cannot get hold of high ron fuel as NF and CVL are very expensive ontop of petrol costs....

viperkick

hello

i got a 93 wrx classic import would i need a octane booster
ive been using optimax
should i be getting my ecu reset
or somehting