I have been using the same set of Et streets for 2 years now. I keep them on the car all summer, and drive on them all the time. I have been to the track over a dozen times with them. They hook real good at the track. How this 12psi in them, and leave at 6000 just sliping the foot of the clucth. With no spining and getting a 1.6s and 1.7s 60fts. So I think they work real well. best 60 ft on them was a 1.675. Going to get a new set this spring.