Your GMC tires have a load index and tire speed rating symbol (see diagram). Use the Tire Finder (above) to find the Original Equipment tire size, tire load index, and a tire speed rating for your GMC vehicle.
A load index is an assigned number ranging from 1 to 279 that corresponds to the load-carrying capacity of a tire. Passenger cars and light-duty trucks generally have a load index number that ranges from 72 to 120.
We recommend replacing your GMC tires with ones that have the same load and speed values as those originally installed on your vehicle. Do not replace tires on your vehicle with a lower load and speed value. Replacing tires that have a higher load and speed value is acceptable.
Note: Winter tires often have lower speed ratings. If winter tires are not available in the same speed rating as the Original Equipment tires, you must not exceed the speed rating of the winter tire chosen.
Tire speed ratings tell the speed your tire can safely maintain over time. The U.S. Department of Transportation (DOT) set the ratings scale, shown below. But tire manufacturers test their own tires and assign their own tire speed ratings. On the sidewall of every tire, you'll find one of these tire speed rating codes:
‡Ad, written estimate, or Internet quote for identical tire(s) from a competing tire retailer/installer located within 100 miles of the dealer required during guarantee period for price match. Offer valid at participating U.S. dealers. Eligible Tire Brands: BFGoodrich, Bridgestone, Continental, Dunlop, Firestone, General, Goodyear, Hankook, Kelly, Michelin, Pirelli, and Uniroyal.