How to Interpret Car Tire Ratings

Video Transcript

"I'm Dave Erb from Dave's Ultimate Automotive, and we're going to be talking about how to interpret the numbers and ratings on the side of a tire. Most common that people out in the world know are the 205 on this particular tire, a 205 70 R15. This is pretty much the size and type of, or the size of tire and wheel that it will fit in. The 205 is actually the width of this tread in millimeters. The 70 is a percentage aspect ratio percentage of the sidewall to the width, in other words the sidewall is 70 percent as tall here as this is wide. And then the 15 represents a 15 inch wheel that this tire would fit on. It's kind of funny you've got millimeters and inches all in the same lettering. The other numbers I want to talk about is the DOT number. Very important, the last four numbers of this DOT are the week and the year that the tire is built. This particular one being an 0908, would be the 9th week of 2008. And that's important because you don't want a really old tire that's been sitting on the shelf for a few years mounted on your car as a new tire. Rubber does become old, it becomes dry, dry rotted and you end up with an unsafe tire. You don't want to be sold a tire represented as a new tire when it's not. A couple of other numbers on here that you should know about, you've got the 95T here and 95 is the load rating or how much weight the tire can hold. A T is the speed rating or how fast the tire could go, you've got upper end cars like Porsche's and Ferrari's and those kind of cars that are up more in the "X", the "Y" 's and the "Z"'s as far as tire speed ratings are concerned. And then there are a couple of other ones on here. One is the temperature rating which is a B on this tire and that is the ability to not absorb temperature as well as to dissipate temperature, how well it does that, and then a traction rating. Traction A, and that's how well it would stop in a wet situation. So those are basically what the different numbers and ratings on the side of the tire mean, so make sure you pick the right one for your car. And that's it!"