Every Tire made has a Load Range or Ply Rating. The Ply Rating comes from the original way Bias Tires were made. The Plys were cotton fiber layers. The more Cotton Layers the more Load carrying capacity they had. This is no longer ture with the modern Radial Tire. They are made with fewer Layers of material that are much stronger. Tire Manufacturers still use Ply Rating to designate the load the Tire can carry. The Tire Manufacture uses Load Range as well as ply rating. These Load Ranges use alphabetical designation. B load rating is a Standard load or 4 ply Rating. C Load Range is a 6 Ply Rating. E Load Range is a 10 Ply Rating. These Load Ratings will be visible on the Sidewall of the Tire. As well will be the Maximum Cold Tire Pressure. Passenger Tires have three different load ranges and can be a 2 or 4 Ply Tire. They will also have the designation of LL for Light Load, SL for Standard Load and XL ro RF for Extra Load. Make sure you look at the Tire Door Placard that is on the inside of your driver's door. This Placard will give you what load your Vehicle Needs. Your vehicle may need a Light Truck Tire which will have an LT in front of the size. LT Tires come in 6, 8, 10 and 12 ply ratings. Load Ranges are C, D, E and F. If you're still not sure what Load Rating you need. Come into Stamps Auto Tire Pros and Let The Trained Staff Help you with your Tire Load Selection.