2011 Mercedes CL-Class Owner's Manual - Page 458

456 Tire labeling The service specifications consists of load bearing index A and speed index B. RIf the size description of your tire includes "ZR" and there are no service specifications, ask the tire manufacturer in order to find out the maximum speed. If a service specification is available, the maximum speed is limited according to the speed index in the service specification. Example: 245/40 ZR18 97 Y. In this example, "97 Y" is the service specification. The letter "Y" represents the speed index and the maximum speed of the tire is limited to 186 mph (300 km/h). REvery tire that has a maximum speed above 186 mph (300 km/h) must have "ZR" in the size description and the service specification must be given in brackets. Example: 275/40 ZR 18 (99 Y). The speed index "(Y)" shows that the maximum speed of the tire is above 186 mph (300 km/h). Ask the tire manufacturer to find out the maximum speed. All-weather tires and winter tires Index Speed rating have been especially developed for driving on snow. An electronic speed limiter prevents your vehicle from exceeding the following speeds: R130 - Tires and wheels mph (210 km/h): All vehicles (except AMG vehicles) R155 mph (250 km/h): - CL 63 AMG R186 mph (300 km/h): - CL 63 AMG (Performance Package) - CL 63 AMG with raised maximum speed The speed index of tires installed at the factory may be higher than the maximum speed that the electronic speed limiter permits. Make sure that your tires have the required speed index as specified in the "Tires" section (Y page 461) for your vehicle, e.g. when buying new tires. More information on reading the tire data can be obtained at any qualified specialist workshop, e.g. at an authorized MercedesBenz Center. Q M+S29 up to 100 mph (160 km/h) T M+S29 up to 118 mph (190 km/h) Load index H M+S29 up to 130 mph (210 km/h) V M+S29 up to 149 mph (240 km/h) i Not all tires that have the M+S identification offer the driving characteristics of winter tires. Winter tires have, in addition to the M+S identification, the i snow flake symbol on the tire sidewall. Tires with this identification fulfill the requirements of the Rubber Manufacturers Association (RMA) and the Rubber Association of Canada (RAC) regarding the tire traction on snow and i Tire data is vehicle-specific and may deviate from the data in the example. In addition to the load bearing index, load index : may be imprinted after the letters that identify speed index B (Y page 454) on the sidewall of the tire. 29 or M+Si for winter tires.