Hi peeps, I have had my sti4 for nearly 2 years now. The engine is standard except from a nice H&S 3" cat-back exhaust system. I change the oil every 3k without fail and it has run religiously on optimax and octane booster.

Last week, I decided to try the Tesco's 99 ron super unleaded.

Now I know that it is going to take the ecu a few tank fulls to adapt to the new fuel, but I have noticed that instead of the 1.4bar max boost which settles to 1.2bar, that I usually get, it is now reading 1.5bar max boost, if not a little more sometimes.
Knock link seems no more lively than before (2 greens max).
I only noticed the increase in boost due to the car feeling more punchy.

Just wondering if it is a combination of the cold weather and new fuel, or if the new tesco 99 ron is responcible.

Cheers guys

 

Cold weather change IMHO.
Is the fuel available all over the UK?
Graham.

 

It is available in the south I think. But as it gets popular, Tesco's are planning its introduction nationwide.