2011 GMC Savana 3500 Passenger Owner's Manual - Page 332

10-66 Vehicle Care The outer tire on a dual wheel setup generally wears faster than the inner tire. Your tires will wear more evenly and last longer if you rotate the tires periodically. See Tire Inspection on page 10‑64 and Tire Rotation on page 10‑64. Also see Scheduled Maintenance on page 11‑2. When It Is Time for New Tires Various factors, such as maintenance, temperatures, driving speeds, vehicle loading, and road conditions, influence when you need new tires. { WARNING If you operate your vehicle with a tire that is badly underinflated, the tire can overheat. An overheated tire can lose air suddenly or catch fire. You or others could be injured. Be sure all tires (including the spare) are properly inflated. See Tires on page 10‑52 and Tire Pressure on page 10‑58 for more information on proper tire inflation. Some commercial truck tires, including Goodyear LT225/75R16 G949 RSA and Goodyear LT225/ 75R16 G933 RSD, may not have treadwear indicators. If the tires do not have treadwear indicators, replace the tires when the tread depth is down to 3.2 mm (1/8 in) for the front tires, or 1.6 mm (1/16 in) for the rear tires. See Tire Inspection on page 10‑64 and Tire Rotation on page 10‑64 for additional information. The rubber in tires ages over time. This is also true for the spare tire, if the vehicle has one, even if it is not being used. Multiple conditions affect how fast this aging takes place, including temperatures, loading conditions, and inflation pressure maintenance. Tires will typically need to be replaced due to wear before they may need to be replaced due to age. Consult the tire manufacturer for more information on when tires should be replaced. One way to tell when it is time for new tires is to check the treadwear indicators, which appear when your tires have only 1.6 mm (1/16 in) or less of tread remaining.