2008 Cadillac STS Owner's Manual - Page 392

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. 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 6-4. 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 5-75 and Wheel Replacement on page 5-80. When rotating P235/50R17 size tires or 255/45ZR18 size tires, always use the correct rotation pattern shown here. If the vehicle has a compact spare tire, do not include the compact spare tire in the tire rotation. After the tires have been rotated, adjust the front and rear inflation pressures as shown on the Tire and Loading Information label. See Inflation - Tire Pressure on page 5-66 and Loading Your Vehicle on page 4-26. 5-74