fuel 95ron

[wrxcook]

Hi my car is a 2003 wrx running super, I usually use hi octane fuels but after stopping at a garage that only had 95ron in the snow feeling lazy I filled it anyway that was a month ago and I'm still using 95ron and the car is still running great I've noticed no difference is there any ill effects, the car is running at 320/310 with the usual mods to get this but I always beleived after mapping I'd have to use hi octane fuel which does not seem to be the case,has anyone get any thoughts on this

[RA Dunk]

If your car has been mapped for higher octane fuel running low octane is not a good idea, it's probably detting it's tits off at high RPM and you don't know about it.

You'll get away with the lower octane stuff if you keep it off boost, but thats all.

[paul555sti]

Have got any form of knock detection?

I wouldn't be taking the risk that you are! Have you not already spent a load on getting your engine rebuilt? Do you want to do that again for the sake of a few quid when filling up?

[wrxcook]

Know idea what knock detection is but think ill stick to the higher octane fuel didn't know there was any risks involved

[RA Dunk]

Yes there are risks and they can lead to an expensive bill.

[andrew_forrest]

The 2003 WRX ECU will start to retard the ignition timing, add fuel and even reduce the boost if it detects significant knock. This will normally reduce performance assuming the existing map is optimised to 99 octane.

It will generally only be noticed at full boost, off boost driveability will remain virtually unchanged regardless of fuel octane.

Andy