Way back in the 70s, the NHTSA established tire ratings for the safety of all on the road, saving lives in the process. In 2023, however, these ratings have become complicated, making buying tires confusing. Use this guide to understand tire ratings, read the ratings on the tire wall, and make the best decision on your new set of tires.

What are tire ratings?

Tires have a Uniform Tire Quality Grade rating (UTQG). This is an important rating to look out for when buying tires. It tells you everything about the tire ratings so you can choose a set that matches your driving habits and vehicle.

A UTQG rating will highlight the following tire attributes and display them as numbers and letters on the tire sidewall:

  1. Treadwear
  2. Traction
  3. Temperature

Treadwear

This rating gives consumers an idea of how long the tire will last. Treadwear is directly related to durability. A tire can’t be used for driving if the treads are fading. 

For example, when a tire is overinflated, it rounds the tire through the middle and adds excess wear to the center of the tire’s treads. If a tire is underinflated and caves in with road contact, the outside, or shoulders, of the tire will receive more wear. A properly inflated tire will evenly distribute friction so the treadwear is manageable.

The higher the treadwear number, the longer the tread is expected to last. Consider this: if one tire has a treadwear rating of 100, and another has a treadwear rating of 200, the latter is expected to last twice as long.

Traction rating

Traction rating is displayed as letters. The highest rating is AA, and decreases to A, B, then C. The higher the letter grading, the better the tire will stop during wet conditions (i.e., it will take a shorter distance). Sailun tires have the highest rating.

Temperature grade

This rating is also displayed as a letter, either A, B, or C. This rating determines the tire’s resistance to heat since they’re subject to high levels of friction on the road. Again, the higher rating will be the letter A, signaling to the consumer that the tire is more proficient at managing heat while driving fast.

This is an important rating to review since one of the main reasons a tire deteriorates over time is heat which affects the rubber. The grade of rubber used when manufacturing the tire determines how well it will be able to disperse the heat accumulated while driving.

Tire speed rating

Also visible on the sidewall of a tire are letters stating the speed a vehicle can maintain safely while carrying the weight defined by the load index. These letters run from A through Z. The higher the speed rating (closer to Z) the better the vehicle will be at handling those elevated speeds.

Here are some examples:

  • T: 190 kph (usually a rating for all-season tires)
  • V: 240 kph
  • ZR: over 240 kph
  • W: 270 kph
  • Y: 300 kph

It’s important to know that these aren’t suggested speeds to drive. They’re simply the maximum speed based on the load being carried before the vehicle loses its performance abilities.

How to read tire ratings on sidewall

Tire ratings can be difficult to understand. The sidewall of a tire has a long string of letters and numbers, and without this guide, who’s to say what they’ll mean to you. However, here’s a straightforward way of reading the specs for all-season tires and performance tires because they aren’t interchangeable for driving.

  • Ensure the tire has the three mountain peak icon which shows that the tire meets the DOT definition of a winter tire. This isn’t necessary for summer tires.
  • The first set of numbers is the width of an inflated tire in inches at its widest point.
  • The second set of numbers is the Aspect Ratio. The lower the ratio, the shorter the sidewall.
  • The following “R” stands for “radial” construction.
  • The number that follows the “R” is the diameter of the wheel (not the tire) in inches.
  • The next set of numbers is the load index which corresponds to the maximum load-carrying capacity of the tire.
  • The following one or two letters are the speed rating: the tire’s maximum speed capability (under optimal conditions).
  • The last couple of letters refer to the type of load amount a tire is designed to handle. XL stands for Extra Load. The absence of a letter value automatically indicates Standard Load which may or may not be represented by the letters SL.
  • And if there’s an M+S, that means “Mud and Snow,” indicating the tire has been designed to perform in these conditions.

The UTQG ratings are read as follows:

  • Traction: AA, A, B, or C. The tire’s ability to stop on wet pavement as measured on a specified government test course. Any tire rated below C is considered unacceptable for road use.
  • Temperature: A, B, or C. The tire’s ability to dissipate heat under a controlled indoor test environment. A tire rated below C is considered not approved for road use.
  • Treadwear: Starting at 100, this is the wear rate of the tire, comparable only to other tires within a tire manufacturer’s line.

When reading the sidewall of all-weather tires and performance tires, look for the same size and speed rating as the vehicle’s previous tires, or whatever the owner’s manual says for the tires. Switching to other sizes and specs either won’t physically fit on the wheel or will negatively impact the driving and lifespan of both the tires and the vehicle.

Sailun tires make the grade

Sailun manufactures tires that continuously test highly in UTQG ratings. We create tires that are both safe and efficient to drive. 
So whether you’re a city driver who mostly drives to work and back, or a country driver who goes on expeditions in the snow, there are top-notch tires to equip your vehicles with at Sailun. Check out our page for tire reviews, informational videos, Sailun in the news, our events, and more. Get into the Sailun community and drive safely.