Just wondering, went to the pump today and saw 100 octane race gas, wondering if it was worth a 1/10 of a tank or so with a ECU reset some time or will i see nothing, except an empty wallet, im betting #2
im stock except my COOoolld air intake (31f out this morn Burr!) :lol:

Well since we run NA cars..we pretty much have no use for higher octane gas unless you've put turbo on your car, swapped out your engine or tuned your modded car for it.

So yes! An empty wallet :D

I've been playing around with adding hexane, isopropyl alcohol, and napthalene. this next paycheck I'll play with some more old school methods of additives.

Higher octane fuel has less energy density (with in the same family). Higher octane fuel is CAPABLE of producing more power in an engine prepared for the higher octane, and its detonation/preignition resistance.

Thus, unless your NA engine is capable of utilizing the added knock threshold, you are just producing less powerful explosions due to the lower energy density.

A turbo car, filling the tank with race gas, can benifit from it by mearly rasing the boost. Rasing the boost is artificially raising compression the compression ratio.

I have variable compression heads (variable cumbustion chamber volume actually) in my NA 2.5. I turn a knob, and I can use any fuel I want. I have even got the car to idle on whisky.

:disco:

how do said "variable compression heads" work?

I'm lying. THis question comes up every so often, so I thought that i would have some fun with it (and give an example of how one might actually find higher than necessary octane useful with an NA engine).

However, Saab has a variable compression engine. It is an inline engine with a hydraulic ram that makes the combustion chamber larger or smaller by squeezing the head closer to the block (there are obviously numerous requirements for this to actually work other than the hinged head and ram) increasing and decreasing the combustion chamber volume by varying the distance between the piston at TDC and the head.

I know that the engine was charged, but I don't remember if they had a fully NA engine set up for this or not (unlikely, since it would be ALOT of farting around for a mostly pointless excercise for a pedestrian OEM application).

Click me for more information (http://www.autospeed.com/cms/A_0458/article.html)

cheeRS,

Greg