Your going to get a lot of answers on this, and here is mine. Take your truck on a dirt road for a few minutes, then get back on the pavement for a few miles, stop your truck,get out and look at the tire sureface, you will see were the dust and dirt has been worn off, if it is clean all the way across the tread put some more air in and repeat, if the outside edge of the tread is dirty, let some air out, and repeat. I like mine just so the outside edge is getting contact, you can also make a line across the tread with chaulk and do the drive, but that is not as much fun.
