What Is a Uniform Tire Quality Grade (UTQG) Standard?
The Uniform Tire Quality Grading (UTQG) system is a set of standards for car tires. Created by the National Highway Traffic Safety Administration (NHTSA) in 1978, it assesses a tire’s treadwear, temperature resistance, and traction.
Since March 31, 1979, all tires manufactured for sale in the U.S. must have UTQG ratings on their sidewall. This is a part of the DOT approval process. The UTQG helps consumers compare tires on a standardized basis. It excludes winter tires and certain light truck tires from grading​​​​.
Components of UTQG Rating
The Uniform Tire Quality Grading (UTQG) system includes three primary components:
1. Treadwear Rating
The UTQG treadwear rating is a three-digit number on the tire’s sidewall, indicating expected tread life. Higher numbers mean longer tread life. For example, a tire with a treadwear grade of 400 should last twice as long as one with a grade of 200. However, this is a relative measure. Actual tire performance varies due to driving style, climate, tire inflation, and vehicle weight​​​​.
Treadwear Rating Chart
2. Traction Rating
UTQG traction grades (AA, A, B, C) rate a tire’s ability to stop on wet pavement. This grading is visible on the tire sidewall. An AA grade signifies better stopping ability on wet pavements than a C grade. It’s important to note that UTQG traction tests focus only on straight-ahead braking, not cornering, acceleration, high-speed driving, or dry road performance​​.
Traction Rating Chart
3. Temperature Rating
The UTQG temperature grade indicates a tire’s ability to dissipate heat, a crucial factor as heat can damage tires over time. Graded as A, B, or C on the tire sidewall, all tires sold in the U.S. must have at least a C rating. Factors like underinflation, high-speed driving, overloaded vehicles, hot weather, and certain road conditions can produce excessive heat​​.
Temperature Rating Chart
How to Interpret UTQG Ratings?
Interpreting the Uniform Tire Quality Grading (UTQG) is quite straightforward. Let’s break it down with an example. Suppose a tire has a UTQG rating of 400 AA A.
- 400 indicates treadwear rating.
- AA indicates traction rating. This is the second part of the UTQG (indicated by letters AA, A, B, or C).
- A indicates temperature rating. This is the last part of UTQG and also a letter grade (A, B, or C).
So, a UTQG rating of 400 AA A suggests a tire with a reasonable lifespan, excellent wet-road braking (AA), and great heat resistance (A). This would be a high-quality tire for various driving conditions. Remember, these are comparative ratings, so they are best used to compare different tires rather than as absolute measures.