What's in a Number? (What Tire Numbers Mean)
August 16, 2020
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.
Charlie's Fast Lube Poplar Bluff
2020 N. Westwood Blvd
Poplar Bluff, Missouri 63901
573-686-5585
http://www.charliesfastlubepoplarbluff.com
Need Service?
More articles from Charlie's Fast Lube Poplar Bluff
Why did my vehicle fail its emissions test?
November 17, 2024
We all want to breathe clean air and keep our planet green. One of the ways to do that is by requiring all vehicles with internal combustion engines to pass an emissions test. Thats because these vehicles can be big polluters. Everyone wants their car to pass the test so they can continue the... More
Oh, Stop! (Disc Brake Service)
November 10, 2024
Every time you drive your vehicle, you wear down your brakes just a little bit. And after a while, that adds up. Gradually, your stopping power isn't like it used to be. Since brakes are one of your vehicle's most important safety features, it just makes sense to keep them performing well. Mos... More
Something to Latch On To (Hood Latch Safety)
November 3, 2024
The other day, a driver was trying to open his vehicle's hood so he could add some windshield washer fluid. But when he pulled the hood release inside the car, nothing happened. Usually, opening any hood is a 2-step process. You pull the hood release (which is usually a handle under the dashbo... More