2009 Mercedes SLR McLaren Owner's Manual - Page 280

Operation Tires and wheels Any tire with a speed capability above 186 mph (300 km/h) must include a "ZR" in the size designation AND the service description must be placed in parenthesis. Example: 275/40 ZR 18 (99Y). The "(Y)" speed rating in parenthesis designates the maximum speed capability of the tire as being above 186 mph (300 km/h). Consult the tire manufacturer for the actual maximum permissible speed of the tire. All-season and winter tires Index Q M+S T H M+S V M+S 1 Load identification Speed rating 1 up to 100 mph (160 km/h) up to 118 mph (190 km/h) up to 130 mph (210 km/h) up to 149 mph (240 km/h) M+S1 1 1 or M+S.for winter tires i Not all M+S rated tires provide special winter performance. Make sure the tires you use show M+S and the mountain/snowflake. marking on the tire sidewall. These tires meet specific snow traction performance requirements of the Rubber Manufacturers Association (RMA) and the Rubber Association of Canada (RAC) and have been designed specifically for use in snow conditions. 1 Load identification i For illustration purposes only. Actual data on tires are specific to each vehicle and may vary from data shown in above illustration. In addition to tire load rating, special load identification 1 may be molded into the tire sidewall following the letter designating the tire speed rating ( page 277). 280