rallyenut

went to the esso station this morning to fill up, however due to being very early-I accidently put normal unleaded 95ron in my my97 wrx!!
to my knowledge its never run on normal 95ron before - i've covered about 20k in it and alway used super 97ron.....until today!!
I drove the 25miles to work and it seems to run ok even on boost.
my worry is that i have heard that it can retard the ecu therefore affect power??
I presume using just one tank with not cause the dreaded '3rd piston melt down'
can anyone offer any advice??-should i have the tank drained?????
any help/comments appreciciated.....
cheers
rallyenut

GavinP

I would suggest you take it easy boost-wise (keep it as low as possible) until you can get some octane booster from a motor accessories store or you have drained the tank.

It is not the end of the world - but your car is more at risk of detonation so don't drive it hard.

IHTH

Thanks

Gavin

Milky

Sounds like your gonna blow a blood vessel in a minute....

To cut a long story short, the ECU will adjust itself to the new 95 RON fuel which will lower power (not much), although as you say there is more chance of pinking when driven hard with this RON fuel. Vice versa the ECU will recognise the new fuel (over a period of time) when you put the next tank of 97 RON in, you could reset the ECU to quicken this procedure up. Not sure if this is neccesary on the later post 97 models.
Just don't do any very hard driving until you put the 97 RON in, simple, no headaches...
You could put in a bottle of octane boost for this tank, not sure if it would mix properly being put in after the tank of petrol.



You'll probabley get a more detailed and technically correct answer from someone else.

Darren.