Here is a question I recently received in one of the BMW forums I moderate: "Speed rating is just about speed, right? I bought Continental ExtremeWinterContact 225/45-17 tires and I can't believe how they messed up my handling. My previous set of Vredestein winter tires were much better for the general handling. These tires are incredibly flexible, way too soft. They make the car wander about all the time. I played with different pressure; no difference."Technically, speed rating is only a measure of the tire's top speed capability. However, there is almost always a correlation between handling and speed rating since higher performance tires tend to be capable of maintaining higher top speeds for a longer period of time. While this is not always true, in the majority of cases lower speed rated tires tend to have slower steering responses and reduced dry grip, especially in winter / snow tires.
Shown below is what each speed rating letter equates to in miles per hour:
|L||75 mph||120 km/h||Off-Road & Light Truck Tires|
|M||81 mph||130 km/h|
|N||87 mph||140km/h||Temporary Spare Tires|
|P||93 mph||150 km/h|
|Q||99 mph||160 km/h||Studless & Studdable Winter Tires|
|R||106 mph||170 km/h||H.D. Light Truck Tires|
|S||112 mph||180 km/h||Family Sedans & Vans|
|T||118 mph||190 km/h||Family Sedans & Vans|
|U||124 mph||200 km/h|
|H||130 mph||210 km/h||Sport Sedans & Coupes|
|V||149 mph||240 km/h||Sport Sedans, Coupes & Sports Cars|
|W||168 mph||270 km/h||Exotic Sports Cars|
|Y||186 mph||300 km/h||Exotic Sports Cars|
To learn more about speed ratings, read "Understanding Speed Ratings."