2009 Mercedes SL-Class Owner's Manual - Page 213

Operation Tires and wheels Replace the tire if you find any of the above conditions. Make sure you also inspect the spare tire periodically for condition and inflation. Spare tires will age and become worn over time even if never used, and thus should be inspected and replaced when necessary. (1.6 mm), we recommend that you do not allow your tires to wear down to that level. As tread depth approaches 1/8 in (3 mm), the adhesion properties on a wet road are sharply reduced. Depending upon the weather and/or road surface (conditions), the tire traction varies widely. Do not allow your tires to wear down too far. Adhesion properties on wet roads are sharply reduced at tread depths of less than 1/8 in (3 mm). Treadwear indicators (TWI) are required by law. These indicators are located in six places on the tread circumference and become visible at a tread depth of approximately 1/16 in (1.6 mm), at which point the tire is considered worn and should be replaced. The recommended minimum tire tread depth for summer tires is 1/8 in (3 mm). The recommended minimum tire tread depth for winter tires is 1/6 in (4 mm). 1 TWI (Tread Wear Indicator) Life of tire G Warning! Tires and spare tire should be replaced after 6 years, regardless of the remaining tread. The service life of a tire is dependent upon varying factors including but not limited to: RDriving RTire The treadwear indicator appears as a solid band across the tread. Storing tires ! Keep unmounted tires in a cool, dry place with as little exposure to light as possible. Protect tires from contact with oil, grease and fuels. Cleaning tires ! Never use a round nozzle to power wash tires. The intense jet of water can result in damage to the tire. Always replace a damaged tire. style driven inflation pressure RDistance Tread depth G Warning! Although the applicable federal motor vehicle safety laws consider a tire to be worn when the treadwear indicators (TWI) become visible at approximately 1/16 in Z 211