You've probably never paid much attention to the writing on the sides of your tires, but they contain a wealth of information. There's a long combination of letters and numbers that can tell you a whole lot about what tires your vehicle was designed to be riding on. Let's check out this example found on an SUV: P245/70R17 108T.
The first letter, P, means it's intended for passenger vehicles. If there's no letter, it means it's a metric tire. If there's an LT at the beginning or end that means a tire designed for light trucks.
Moving on to our example, the 245 shows how wide the tire is in millimeters from sidewall to sidewall. The number that follows in our example, 70, means the height of the tire is 70% of its width. The letter after that in our example, R, describes the type of tire (on this vehicle, radial). Following that is the diameter in inches, in our SUV example, 17 inches.
How much load the tires' sidewalls are designed to take is what that next number is all about (108 in our example). The higher the load index, the more weight the sidewalls can take. And the last letter is the speed rating of the tire, in our example, T. The further along in the alphabet that letter is, the higher its speed rating. So now you know what those letters and numbers mean. But why are they important?
When you are getting ready to replace those tires, those numbers are telling you what the original equipment was when your vehicle was new. Sticking with the same rated tires is always a good idea. If you don't know what you're doing, trying different sized tires and wheels can cause real issues when it comes to performance and safety, considering all the computerized systems now found on vehicles. When in doubt, consult your service advisor when it comes to buying new tires. He or she knows what those tire numbers and letters mean… and a whole lot more.
Tuffy Fort Wayne - Dupont Rd.
1910 W. Dupont Rd.
Fort Wayne, IN 46818
December 5, 2021
Most light vehicles (under 10,000 pounds/4,500 kg) in North America sold from 2008 model year on have a feature that many people are confused about. It's the tire pressure monitoring system (TPMS). You may have some experience with it yourself if you own a newer vehicle. Vehicles with TPMS hav... More
November 28, 2021
What a convenience power door locks are on a vehicle. The latest don't even require you to push the button on the key fob; all you have to do is have it with you. But sometimes there's a component of power door locks that can fail, especially when they are used several times each day. Those ar... More
November 21, 2021
If you were to name the most important safety feature on your vehicle right now, what would your answer be? A lot of driving experts would agree that its your brakes. Most newer vehicles use a well-engineered and efficient style of brakes called disc brakes. The name disc brakes comes from one ... More