My 2001 F150 4x4 actually pulls slightly left, even if I'm in the right-hand lane. I've also checked tire pressue, brakes, etc.... Every time I take it in, I have them check this and it comes back advising everything is within specs. It has 25,000 miles and the tires are not worn uneven. Of course I rotate them every 5,000. Guess I just have to live with it. I just like driving with my right arm resting on the middle arm rest, but it gets a little tired, on long drives, when I constantly have to keep slight pressure on the wheel to keep it in the lane.