Ive been reading all about nitrous tuning as were about to try to get a car tuned on a healthy shot and Ive seen very little reason to run race gas+nitrous unless your spraying a huge shot on a nitrous car. For an everyday car only spraying a 75 shot, Id say just stick with 93 and retarded timing. Were using a zex kit on our car too, cant wait to see what it puts down on spray.