I bought a new nissan frontier sv crew can pick up. it has a terrible vibration from 60-80 mph. i have taken it to the dealer a couple of times. they changed out the tires and then told me it is normal for all of these vehicles. i believe this is a safety issue, because i can not drive very far without my hands going numb. it is impossible for me to drive it any distance on the freeway because of this issue. i am not certain it is the tires, but nissan claims it is normal.