I agree with lyonsd, about the pump gas thing. The low 12s numbers at the track mean nothing when you get beat by an LS1 or something on the street, because you were running low boost on 93 octane. You can tune a car to run well on pump gas. And with the right mods you can run a high 12 in street trim, which is more than enough, for most cars on the street. And these cars can be fast on pump gas, you just have to tune them right. Alky is a great option that everybody should look into, but if your modded GN can't take a stock or lightly modded lighting in full street trim, then something is definately wrong, and you need to get it right on 93 octane before you dump in the good stuff.