What is the difference between AT tires and Light Truck tires?

What is the difference between these light truck tires?

• my current tires are pirelli scorpian str 265/70/17. i was going to upgrade them to hankook all terrain rf10's 265/70/17. the guy at americas tire co said that the hankook tires won't be very good since i haul alot of heavy stuff sometimes. what is the max weight for each tire at a certain amount of psi. so far i found that hankook tires are 44 psi at 2,535lbs, while pirellis are 80 psi at 3195 lbs. what is the main difference of these tires?

• Answer:

  The problem is you have left most of the tire size off. Yes ALL of those numbers and letters are important. The numbers (265/70R17) provide only dimensions. There is a lot of stuff you are leaving off that is critical to picking the right tire for a truck. Light Truck Metric sized tires in an E Load Range have a size that reads like this: LT265/70R17 121/118R. These will have a maximum load carrying capacity of 3,195 pounds at their maximum inflation pressure of 80 psi. If you have a 3/4 or 1-ton truck it almost certainly REQUIRES LT-Metric sized tires and high inflation pressures of up to 80 psi. Tires sized using the Passenger Metric system would read something like this: P265/70R17 113T. Notice the P instead of LT at the front (which means the tire is equivilant to Load Range B) and the different Load Index numbers at the end which indicate load carrying capacity. With the P-Metric tire maximum inflation pressure is limited to 44 psi but the maximum load capacity occurs at only 35 psi with just 2,535 pounds per tire. A P-Metric tire belongs on nothing bigger than a half-ton pickup where this kind of tire size is normally standard equipment. LT Metric tires in an E Load Range can be used on a light duty 1/2 ton truck but you have to run much higher inflation pressures. At the 35 psi normally used on a light-duty (1/5-ton) truck load carrying capacity is only 1,890 pounds for the LT-Metric tire. You have to bump it up to 55 psi to match the load capacity of the P-Metric tire at 35 psi.