The truck was not designed for anything other than standard-size tires, so you're going to have to talk with a tire salesman or someone else who has already wrecked their truck by doing that.
Any salesman who would sell you larger tires considers grabbing your money more important than your legal ramifications. If you want me to, I'll post my standard reply about how this adversely affects braking, handling, stopping ability, and steering control, but I won't waste my time if you don't want to hear it.
The key alignment angle that will be affected is called "scrub radius". Lawyers and insurance investigators know all about it and they WILL convince a jury that you were partly at fault for the crash when the other guy ran the red light. They'll argue you were less able to avoid it, and they will be right. Scrub radius is a non-adjustable geometric angle of the suspension system that was carefully-designed in. It is changed by using taller tires, wheels with a deeper offset, and possibly wider wheels. Some lift kits change it too.
Lowered cars are just as susceptible to these problems as are raised trucks. If you want to switch to a different size tire, use one that is listed by the manufacturer as optional equipment. You'll need to change your speedometer too. On older vehicles that is done by replacing the gear on the end of the speedometer cable with one with the correct number of teeth. The dealer's parts department can select the right gear. On newer trucks, that is programmed in and has to be changed by the dealer. That's called the "pinion factor". They enter the axle ratio and tire size to make the adjustment.
Thank you for not wanting to install a lift kit. When I become president, I'm going to outlaw them. From my experience on the race track, I understand how ride height interacts with all the other aspects of the suspension system. As a suspension and alignment specialist, I understand the importance of making sure ride height is right on the money, and what happens when you mess with it. At the dealership, I had the owner's blessings to refuse to work on any vehicle with altered ride height. Doing so would have made me and the dealership party to any potential lawsuit.
Friday, September 26th, 2014 AT 8:19 PM