Interesting. I have had my F150 SuperCrew in twice in 2 weeks for vibration. the tires were out of balance the first time (3000 miles). 2 weeks later I was back in and 3 of the 4 were out of balance again with 600 miles (highway only) logged on them. 3 days after getting them balance the vibration came back. I live in MN and I thought maybe it was tire pressure due to cold weather, they were fine when I checked them. Interesting to hear what you had to say. I am going back this week and if it rears its ugly head again I am asking for new tires.