2009 Mercedes SL-Class Owner's Manual - Page 234

Operation Tires and wheels Production options weight The combined weight of those installed regular production options weighing over 5 lbs (2.3 kilograms) in excess of those standard items which they replace, not previously considered in curb weight or accessory weight, including heavy duty brakes, ride levelers, roof rack, heavy duty battery, and special trim. Rim A metal support for a tire or a tire and tube assembly upon which the tire beads are seated. tread and sidewall. Tire manufacturers also must indicate the ply materials in the tire and sidewall, which include steel, nylon, polyester, and others. Sidewall The portion of a tire between the tread and the bead. Tire speed rating Part of tire designation; indicates the speed range for which a tire is approved. PSI (Pounds per square inch) A standard unit of measure for air pressure. TIN (Tire Identification Number) Unique identifier which facilitates efforts by tire manufacturers to notify purchasers in recall situations or other safety matters concerning tires and gives purchasers the means to easily identify such tires. The TIN is comprised of "Manufacturer's identification mark", "Tire size", "Tire type code" and "Date of manufacture". Total load limit Rated cargo and luggage load plus 68 kilograms (150 lb) times the vehicle's designated seating capacity. Recommended tire inflation pressure The recommended tire inflation pressure for normal driving conditions is listed on the Tire and Loading Information placard located on the driver's door B-pillar and provides best handling, tread life and riding comfort. If so equipped, supplemental information pertaining to special driving situations can be found on the tire inflation pressure label on the inside of the fuel filler flap. Traction Force exerted by the vehicle on the road via the tires. The amount of grip provided. Tire load rating Numerical code associated with the maximum load a tire can support. Tread The portion of a tire that comes into contact with the road. Tire ply composition and material used This indicates the number of plies or the number of layers of rubber-coated fabric in the tire Treadwear indicators Narrow bands, sometimes called "wear bars" that show across the tread of a tire when only 1/ in (1.6 mm) of tread remains. 16 232