How to Read and Understand Tire Size and Specs

July 19th, 2022 by

How to Read Your Car Tires

How to Read Your Car Tires

Your fuel economy depends on your engine, powertrain, and your TIRES! Tires also greatly affect your stopping distance. Often times we don’t think of our tires until there is a need to replace one or more.

If you look at the side wall of your tire you will see several numbers and letters that look more like a VIN number. The first segment tells you the type and size of the tire. P indicates that the tire is a P-Metric tire. So what does that mean? It means the tire was created specifically for passenger vehicles and follows standards set by the National Highway Traffic Safety Administration. If you instead see LT then that particular tire was made for Light Trucks and has been made in a way that follows national safety standards. The following three numbers inform you of the tire width in millimeters.

So if you look at your tire and see P275 then that particular tire is a passenger type and is 275mm wide.

Following a forward slash are two numbers that indicated the tire aspect ratio followed by the construction indicator and the wheel diameter. The aspect ratio of the relation of the height of the tire to the width of its midsection. The letter following the aspect ratio tells you about the tire construction. The R stands for Radial so the layers of rubber run radially across the tire. The last two numbers of this segment represent wheel diameter in inches.

So if you see /70R18 on your tire then that tire’s height is equal to seventy percent of its width, the layers run radially across the tire and the wheel has an 18-inch diameter.

The final set of printing on the tire stands for Load Index and Speed Rating. A load index is a two-digit number that tells you the maximum load that can be put on the tire when you look at the tire load index chart. following the Load Index is the Speed Rating. The Speed Rating is represented by a letter that indicated the top speed capability of the tire. This letter also involves an index.

If you see 98H then after checking the Load Index and Speed Rating charts I then know this tire can hold 1653 pounds and has a maximum speed of 130 miles per hour.

Have more questions? Contact our service center or check out our Hyundai Tire Center.

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