For the last two weeks, I have been running them at 38 and 40. Unfortunately, after 4 balancing attempts at two different stores and replacing two of the new tires, the wheel shake at 60+ mph is not going away. I am going to order Yokohama Geo Lander GO15. There specs say that they have narrower tread width so may be that will help. Really wanted to like these tires but oh well.