Car #: 58
Year : 1990 Posts: 61
Hey guys, I am headed to the NJMP Driver School this afternoon and need to pickup some fuel for the car. Does NJMP have 94 octane fuel for purchase on site? Anywhere near by that has it available? Or should I just get some 93 at a local station?
Car #: 12
Year : 1990 Posts: 830
You'll get more performance out of lower octane fuel sometimes (depends on teh fuel). The octane is added to prevent detonation, not to make it more "powerful". Its used in high performance cars because the temps and compression are often higher. I saw a nice bump on the dyno last time with 87 octane fuel over the higher octane gas from the same gas station.
That being said, the last thing you want is detonation, and offsetting the risk of that by using higher octane fuel and giving up a bit of power might be an OK compromise for some people.
There was a thread on this just recently.
Also, make sure you get gas from a busy gas station, the stuff that's been sitting in the bottom of someones tank for a month may have contaminants, water etc... learned that one the hard way.
Some great reading for those who don't understand the differences between detonation and pre-ingnition and the causes of both. It will also help you understand the need for different octane requiresments. Now the only trick is to figure out exactly what octane is correct for your engine and use.
Car #: 00
Year : 1992 Posts: 294
quote:Originally posted by d mathias: Compression ratio determines the level of octane needed to prevent detonation. Nobody here has a CR higher than stock do they?
c/r is not the only thing that determines octane requirements. If you advance the timing like we can on 1.6 to say 16-18 degrees and run leaner than stock AFR you'll need a higher octane fuel(slower more controlled burn) to prevent detonation.
I certainly hope nobody here has more than stock c/r