2015 Cadillac XTS Owner Manual - Page 315

10-46 Vehicle Care How to Check Use a good quality pocket-type gauge to check tire pressure. Proper tire inflation cannot be determined by looking at the tire. Check the tire inflation pressure when the tires are cold, meaning the vehicle has not been driven for at least three hours or no more than 1.6 km (1 mi). Remove the valve cap from the tire valve stem. Press the tire gauge firmly onto the valve to get a pressure measurement. If the cold tire inflation pressure matches the recommended pressure on the Tire and Loading Information label, no further adjustment is necessary. If the inflation pressure is low, add air until the recommended pressure is reached. If the inflation pressure is high, press on the metal stem in the center of the tire valve to release air. Recheck the tire pressure with the tire gauge. Return the valve caps on the valve stems to prevent leaks and keep out dirt and moisture. Professional Vehicle If the vehicle has P245/45R19 size tires, the cold inflation pressure is 35 psi (241 kPa). If the vehicle has 235/55R18 size tires, the cold inflation pressure depends on the vehicle mass and should be determined by the vehicle coach-builder. A Tire and Loading Information label provided by the final stage manufacturer should be attached to the B-pillar on the driver side of the vehicle. If the final stage manufacturer's label is not present, contact the coach-builder. Do not use the tire pressures indicated on the General Motors label. These tire pressures are for the incomplete vehicle and are not the correct tire pressures for the completed professional vehicle. The Tire and Loading Information label on the vehicle indicates the original equipment tires and the correct cold tire inflation pressures. The recommended pressure is the minimum air pressure needed to support the vehicle's maximum load carrying capacity. See Vehicle Load Limits on page 9-10. How the vehicle is loaded affects vehicle handling and ride comfort. Never load the vehicle with more weight than it was designed to carry. When to Check Check your tires once a month or more. Do not forget to check the spare tire. If the vehicle has a compact spare tire, it should be at 420 kPa (60 psi). See Compact Spare Tire on page 10-73 and Full-Size Spare Tire on page 10-74.