^ i would agree.. plus, additives in fuel should help keep the engine clean. Petro Canada adds more fuel cleaners in its higher octane fuels then the lower ones.

 

but wouldn't be less expensive to buy a very good cleaner (Sea Foam as exemple) and then get regular gaz ? Sea Foam could be use each 5000km and would do a better job than the Petro Canada Supreme Fuel.

That's what I think but I might be wrong.

 

Yes, high octane is better then 87 because of the some additives plus it will help restrict the amount of carbon build up inside the combustion chamber. 87 has more build up. I would use maybe 89 max in RA. I run 110 now but mine isn't street legal either. I took apart my engine at 80k running nothing but 91 and i have very little carbon deposits. You will always have some carbon build up because of the Hydrocarbons in fuel. No way of getting around it.

 

i run nothing but 93 in all my cars- always have...only use lucas injector cleaner every other tank..no problems..all run great..the subaru has 130k on it and runs like a race car still.

 

87 octane sucks, ive been putting it in my car since new and all it does is ping like crazy. the last straw was this past weekend when i filled up and the gas must have been really cheapy crap b/c my car hesitates everytime im on the throttle(either that or my MAF is dirty). either way my next fill up will be 89 or 91.

 

I agree ^ , as mentioned later in the thread there is always going to be carbon build up of some kind but it will be alot less prominent for higher octane fuels.