Updated March 16th, 2017

Sterling, Virginia - Speed ratings are an important element of understanding more about you tires , as they will give you a good idea of the type of performance you can expect from whatever tires you buy. The United States Department of Transportation (USDOT) established speed ratings as a way to let you know what type of speeds a tire can safely handle on a consistent basis. A higher speed rating means that a tire will perform well in terms of stability and handling even at higher speeds. To be clear, however, tires with higher speed ratings typically perform better overall, even at lower speeds.

So how are speed ratings measured? The USDOT has created a speed ratings scale comprised of several alphabetical letters, each one symbolizing a certain speed at which the tire reaches peak performance level. For example, a tire with a speed rating of "Q" can safely sustain speeds of up to 99 miles per hour. What this means is that if a "Q"-rated tire were to be subjected to speeds higher than 99 mph for any length of time, it could potentially create unreliable performance. Speed ratings will let you know what type of stress your tires have been designed to handle, and at what point your tires may perform with decreased stability.

You can find the speed rating for any tire by looking on its sidewall. The speed rating is typically found right after the series of numbers and letters representing the size of the tire. For a tire with the numbers "205/55R16 91T" on its sidewall, the "205/55R16" represents the tire's size, and the "T" at the very end represents the speed rating, which means that this particular tire can safely perform at speeds of up to 118 mph.

When you're shopping for new tires, keep in mind that you should only pick tires that have a speed rating that at least matches what the manufacturer recommends for your vehicle. If you want to choose a tire with a higher speed rating, that's no problem, but make sure that you do not choose a lower speed rating that what has been recommended. Regardless of speed rating, it is always a good idea to obey all designated speed limits, as this is the best way to ensure your safety on the road.

Hogan & Sons Tire and Auto is the source of vehicle educational information. Hogan & Sons Tire and Auto recommends regular vehicle care and maintenance to avoid costly repairs in the future.

*Always check your owner’s manual for your vehicle model’s specific instructions before attempting any type of repair. Copyright Hogan & Sons Tire and Auto March 2017