Regular vs Premium
 

Just curious....

Would there be much of a difference in using the premium (91) over the regular (87) in my 96 Si (EX)? It's pretty much stock except for the CAI with K&N. Any advantages or disadvantges of one over the other?

THNX

RE: Regular vs Premium
 

Octane ratings are pretty much just numbers correlating to detonation resistance. If you have 87 octane, you have an 87% octane rating with a 13% heptane reading. Heptane burns fast, Octane doesn't. If you have more octance, your gas burns "slower" on the combustion cycle. If you run 87 octance in a car that needs 100, you'll get detonation because the fuel is burning before it needs to, in essence. The basic rule is that the higher the compression, the higher the octane needed to resist detonation. I've seen built, boosted cars gain quite a few poines after swithing to race gas, but those are tuned, turbo'ed and street (il)legal. I wouldn't recommend switching gasses necessarily unless you have a real reason to.

RE: Regular vs Premium
 

I would check you owners manual if your car is close to stock some cars are made to drive on different octane levels.

RE: Regular vs Premium
 

Unless you have alot of aftermarket upgrades I wouldn't spend the extra money, but that's just me. IT's not going to give you much gain if any on a stock ex.

RE: Regular vs Premium
 

theres really no point. you're just wasting your money.

RE: Regular vs Premium
 

you can also add a little bio-desil to your gas to rais the octane

RE: Regular vs Premium
 

You could use high octane and advance your timing. That will give you a couple horses, but IMO its not worth it.

RE: Regular vs Premium
 

I wouldnt mess with the timing. Just run 87, I wish I could use 87.......its much cheaper.

RE: Regular vs Premium
 

Who told you that diesel adds octane???????????

Diesel is CETANE. Totally different kind of fuel, made for compression ignition.

RE: Regular vs Premium
 

Diesel is too thick for your fuel injector to spray. But diesel does resist detonation more than gasoline. Typical compression ratios for diesel engines are in the 20:1 range.