2010 Cadillac STS Owner's Manual - Page 423

10. After hearing the confirming single horn chirp for the driver side rear tire, a double horn chirp will sound to signal the tire matching mode is no longer active. Press the push‐button ignition switch to Acc. 11. Set all four tires to the recommended air pressure level as indicated on the tire and loading information label. 12. Put the valve caps back on the valve stems. Tire rotation is recommended if the vehicle is equipped with P235/50R17 size tires on all four wheel positions or 255/45ZR18 size tires on all four wheel positions. These tires should be rotated every 5,000 to 8,000 miles (8 000 to 13 000 km). See Scheduled Maintenance on page 7‑3. The purpose of a regular tire rotation is to achieve a uniform wear for all tires on the vehicle. This will ensure that the vehicle continues to perform most like it did when the tires were new. Any time you notice unusual wear, rotate your tires as soon as possible and check wheel alignment. Also check for damaged tires or wheels. See When It Is Time for New Tires on page 6‑69 and Wheel Replacement on page 6‑74. Tire Inspection and Rotation We recommend that you regularly inspect your vehicle's tires, including the spare tire, for signs of wear or damage. See When It Is Time for New Tires on page 6‑69 for more information. Tire rotation is not recommended if your vehicle has P235/50ZR18 size tires on the front wheels and P255/45ZR18 size tires on the rear wheels. Different tire sizes should not be rotated front to rear. Each tire and wheel should only be used in the original front or rear position it is in. 6-67