john shea

Will I gain .1 with an underdrive pulley or will it be less?

Colonel

Yes...possibly no. It depends. The more RPMs you turn, the higher the gain (the faster we turn the accessories, the more we stand to gain by slowing them down.) The slower your car, the more you gain (tenths are harder to come by the quicker you go.)

But generally speaking, yes. About a tenth and a MPH.

Ferocity02

iTrader: (60)

Usually they show about a tenth gain yes. Not all cars are the same, hell you might lose time, but it's highly unlikely.

Bad Blu Formula

iTrader: (3)

Just do it. Every little bit helps.

Kenny D

I gained .50 but that was with slicks also. So those probally slowed me down. They usually do get .1