When customers visit our Centennial, Aurora, and Denver locations, they often have questions about how their cars are manufactured, rated, and prepared for the lot. One such question is, “What is the speed rating on tires?” As simple as it sounds, the speed rating tells drivers much more than how fast their vehicles can go. The rating can also tell you much about your car’s overall condition and how well it fits your driving needs.
What Exactly Is a Speed Rating?
A speed rating indicates the maximum speed a tire can reach before it no longer performs as designed. The speed rating is listed under tire code, which can be found in several areas of your car. Try the glove box, driver’s side door jamb, or gas tank hatch. Should it not be listed there, the tire speed rating is always in the owner’s manual. If all else fails, check your tires’ sidewalls. The speed rating is generally the last character sequence in the tire code.
Sidewall Codes Decoded
The tire sidewall code usually begins with a letter, such as P for “passenger car.” Width is listed next, then aspect ratio. For example, if your tire code begins with P 225, the width of the tires is 225 inches. Another letter, such as R, will indicate construction, followed by rim diameter and load index. Your speed rating is the final letter on the sidewall, such as V, S, or R.
Decoding Your Speed Rating
Now that you know where to find the speed rating, it’s time to decode it. Tire speed ratings are given alphabetically using letters A through Z, although some letters are never used. For example, speed ratings of I, O, and X don’t exist. Some speed rating charts do not include all existing letters, and some letters are followed with a number. Tires with speed ratings of A are generally the lowest, while ratings of A1, A2, and A3 correspond to different levels of the same rating.
The higher the letter in the alphabet, the higher your tires’ maximum speed, generally. Tires rated N are equipped for a higher maximum speed than those rated L. Consequently, a rating like V is the best tires can have. It’s important to note not all vehicles are built only for speed, and that you should choose a vehicle based on your driving lifestyle. If the heaviest driving you do occurs during your commute, a speed rating of L, or even something like G, might be fine.
Additionally, note that the letter system is a bit quirky. Tire speed ratings have European roots, so letters may not fall in what we consider alphabetical order. One example is a rating of H as it actually falls between U and V, not after G. This makes H a higher speed rating than you might expect. If you are unsure of your speed rating even after decoding, ask a technician for help.
Tire speed ratings are tested in an auto manufacturer’s lab under controlled conditions, so understand that the speed rating is the best estimate for your vehicle, and does not include factors such as alignment, weather, and eventual wear and tear. We never recommend that you place your tires under maximum speed capability, especially on rough roads or during inclement weather.
If you have questions about the speed rating on tires or similar automotive concerns, we invite you to visit one of our locations in Centennial, Denver, or Aurora or schedule an appointment online. We look forward to serving you.