I have a Laramie as well, with the 20in. Bridgestones. Took my truck on a 20 minute ride at 60 mph. I reset the fuel meter. Only got 16.2 mpg on the trip, and only hit 2 lights. Otherwise, 60 mph back and forth for 20 minutes. Not impressed with the mpg at all. Oh, and it was the most intolerable ride as the truck vibrated so badly between 60 and 70 mph. I took a 2nd trip, at 60 mph with MDS off using the gear select. It did nothing to improve the ride, just made it louder in the cabin, and only got 14.8 mph. I seriously doubt this truck could ever get above 17 mpg, and even then, the truck is not driveable above 60 mph. Yet, I've taken in to the dealer who says nothing is wrong, but gave me a 'complimentary' tire balance which did nothing. I'm not even sure they actually did anything except mark it on the paper. Has anyone found any solution to this terrible shake/wobble?