I went from a 29.5x13.5 M/T to a Hoosier 31x14. Car slowed up .04-.05 in the 1/8th right after I put the Hoosiers on. The next time I needed tires I went back to the M/T 29.5x13.5 and the car ran the same as it did with the Hoosier. I've also had to put M/T 29.5x11.5 on the car in pinch and it ran the same as it did with the 29.5x13.5. Since Goodyear bought M/T they eliminated alot of the tire sizes offered by M/T.