02saleen281

i bought a new saleen n/a, on the dash it says use premium unleaded, and in the fuel door it says use only 91 octane fuel, whats the reason for this? and does it make that much of a difference?

makarovboy

Probably due to the higher compression. Premium is more unstable than regular, slower burning, and does not need the timing bumped up to it's outer limits to maintain performance. (not to mention detonation, big engine killer).