I have put my Code3 pulley to the test against a friend countless times in stock and moded form, I have achieved two car lengths improvement from 0-70mph, however.... keep in mind I have an Intake as well. With my intake we were dead even every time so ive been able to observe and take note of gains. I deffinately felt in 2nd gear onwards was where i could see the car start to pull away to an eventual two cars by about 70mph.