What octane should i use ??

[ebpda9]

Originally posted by juvenile
How about for let's say a Civic.
Stock, NA or FI. Would there be a difference?

And how about for my stock Concorde?

higher octane means that the fuel can withstand high compression ratio without dentonating itself before the spark, which will cause the engine to knock. i don't know about the cr on a civic but i guess it is under 9:1 since it uses 87 octane. to use a higher octane with the same performance you need to advance the timing. using higher octane on an engine will cause misfire, rattling and sometimes knock. also your gas mileage will become gas yardage. as far as your concorde goes stick with whatever says in the owner's manual.