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What Do Tire Numbers Mean?

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“If you’re like most people, you probably take your car’s tires for granted. You know that they are important to the safety of your vehicle, but do you ever stop to wonder what each number on a tire represents? What if one day you found out that those numbers were quite significant? What” if you found out that those numerals meant something?

Tire service type ratings

are crucial to the safe operation of motor vehicles. Understanding what they mean will help you make your tire purchase decisions with complete confidence.

Tire Ratings and Numbers

There are three superior numbers and one letter that appear on just about every tire:

UTQG – Uniform Tire Quality Grade

DOT – Department of Transportation

TIN – Tire Identification Number CAP – Speed Symbol

The first number of the three on the sidewall is known as the Tire Quality Grade. This letter grade ranged from A to C and was put into place by the National Highway Traffic Safety Administration (NHTSA). The UTQG describes a tire’s performance in a laboratory setting. So it might not reflect real-world driving conditions. Plus, it measures a tire’s ability to stop on wet pavement and was not created with dry conditions in mind.

The second number of the three is known as the Service Grade. This rating represents a tire’s durability. The higher the number or letter that appears here, the longer your tires will last. It also reflects how well they resist tread wear and how much better they do in the snow. The numbers range from 0 to 200, while the letters range from A to C. The lower the number or letter, the shorter your tire life will be.

The last number of three is the Speed Symbol and appears on all passenger car tires (not light truck, motorcycle, or trailer tires). It represents the tire’s speed capability and is not confused with the speed ratings that show how fast you can safely travel in a particular tire. Most passenger car tires have a maximum inflation pressure of between 36 and 44 psi, suggesting a total speed of 80 mph. Tires with a Z rating will allow speeds up to 14mph.

Tire Sizes Explained

Section width of the tire

Tires are sized by their width, aspect ratio, diameter, and rim size to ensure that they fit onto your vehicle. The first number you’ll see in the size of a tire is its width. This number refers to the tire’s section height (from sidewall edge to sidewall edge) or how wide it is across its tread. This number is given in inches.

The second number you’ll see is the aspect ratio, which refers to a tire’s sidewall height as a percentage of its section width. This number is also given in inches. The higher this number, the thicker your tires’ sidewalls will be. Thicker sidewalls mean more stability for your vehicle and more comfort for you.

The third number refers to the tire’s diameter, which is how far it extends beyond its sidewall. This measurement is given in inches. It can be used to describe the size of your tires when stacked on top of each other or if they are mounted onto a wheel hub with an inner rim diameter. The last number included in a tire is its rim size. This number represents the diameter of your wheels’ hub opening.

The letter that closes off the sidewall of a tire’s size is the LT (Light Truck) designation, which identifies this tire as being designed to fit most light trucks and SUVs.

All-Season vs. All-Weather (Summer vs. Winter)

All-Season tires are meant to be used throughout the year in different weather conditions. However, they shouldn’t be considered Snow or Summer tires. All-Season tires can handle light snow and rain exceptionally well but do not perform very well when faced with heavier loads than the average driver faces every day. They also tend to wear out faster than Summer or Winter tires.

Tubeless Tires Explained

A tubeless tire is different from a conventional one in the following ways: It doesn’t use inner tubes to hold air. It is lighter weight. The absence of an inner tube helps improve traction by preventing punctures and cuts on the sidewalls that would otherwise lead to air leakage. The lack of an inner tube enhances the tire’s fuel efficiency and ability to hold onto the road.

What Do Tire Number Indicate?

Tire number indicators show the manufacturing plant and date of production. The first two digits represent where it was made, while the third represents the year it was produced. For example, 4205 means that your tire was manufactured at a Bridgestone plant in Japan during the 42nd year after World War II (1985).

Like many other parts of your car, tires are built to last. However, it’s still possible for them to go flat or wear out before you intend to replace them. That’s why tire pressure monitoring systems work by constantly scanning the air pressure inside your tires while driving.


These are only a few of the essential things you need to know about your tires. If you want more information, it’s advised that you contact a professional so they can inspect and measure your tires. It may seem like a small part of your car, but it is necessary for safety on the road.


Q – Are tires with an R rating safe to drive in the rain?

A – Yes, they are. If you have a car with tires that have an R rating, it means that it can handle light rain quite well. However, if there is heavy rain for a prolonged period or the authorities are issuing flood warnings in your area, it’s best to stay off the road.

Q – Can tires with an N rating also have an R or S rating?

A – Not all tires are designed for the same weather conditions. There are Rain tire ratings, All-Season ratings, Snow Tire Ratings, and Summer Tire ratings. N-rated tires are meant for everyday driving in dry weather. R and S rated tires are indicated for both rain and snow, while T rated tires have a summer tire rating which means they can grip the road during dry, warm conditions.

Q – What kind of tire should I get if I want better traction?

A – Different types of tires provide varying levels of traction. If you want to improve your car’s handling and grip on the road, you can either install a new set of tires or buy tire chains.