Numbers and Letters on Tires Explained - Simple and Easy

February 14, 2024

If you've looked at your tires, you've probably noticed a couple of numbers and letters. But what do they mean? We will look at exactly that while making it simple and easy to understand. If you continue reading, you will find out about all of the numbers and letters on your tires. Keep in mind that we will start with the symbols from left to right.


Tire Type - First From Left To Right

The first symbol on your tires is usually a letter, specifying the type of vehicle the tires are made for. They can be either for passenger vehicles (P), light trucks (LT), or special trailers (ST).


Tire Width - Second From Left To Right

Following the first letter is a three-digit number specifying the tire's width. It measures the distance from side to side (looking at the tire head-on/the direction it moves in). It is measured in millimeters.


Aspect Ratio - Third From Left To Right

To put it simply the second pair of numbers is for the aspect ratio. It means that the tire's sidewall is, for example, 65 percent of the width.


Construction Type - Fourth From Left To Right

The second letter on your tires represents the construction type. It can be one of three types: D (radial construction), R (diagonal/crisscross construction), and F (run flats).


Wheel Diameter - Fifth From Left To Right

The third set of numbers specifies the diameter of the wheel in inches. It is measured from two opposite seal areas, where the tire makes a seal with the rim.


Load Index - Sixth From Left To Right

Explaining the load index is complex. To put it in simple terms, it is the sixth pair of symbols measuring the weight the tire can support.


Speed Rating - Seventh From Left To Right

The last symbol on your wheels is a letter assigned to the speed rating. There are charts with all of the letters, which correspond to a certain speed - they start at A1 and end at (Y)


Tire Services At Auto DR!

If you are looking to buy a new set of tires, or need any sort of wheel-related service, make sure to stop by Auto DR. Our team specializes in tire procedures, so the results will certainly meet your expectations.


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