Lesson: Treadwear, Traction and Temperature Grades

Educational guide · sources linked inline · reviewed November 8, 2026

Quick answer

In this lesson you’ll learn to read the Uniform Tire Quality Grading System, the three government grades on the sidewall of every passenger vehicle tire sold in the United States. ^[NHTSA]

In this lesson you’ll learn to read the Uniform Tire Quality Grading System, the three government grades on the sidewall of every passenger vehicle tire sold in the United States. ^[NHTSA] By the end you’ll be able to compare two tires the way a technician would.

What this means for you

Standing in a tire shop staring at a wall of black rubber can make anyone feel out of their depth, especially when the price tags are high. Here’s the reassuring part: the U.S. government already graded most of those tires for you, and the grades are printed right on the sidewall. Once you can read three simple codes, you can compare tires calmly and ask better questions, instead of just hoping the salesperson is right.

Key terms

UTQG: Uniform Tire Quality Grading System, the U.S. government rating for treadwear, traction and temperature resistance.
Control tire: The reference tire graded 100 that other tires are compared against for treadwear.
TIN: The DOT Tire Identification Number; its last four digits show the week and year the tire was made.
Rolling resistance: The energy a tire loses as it rolls, which affects fuel economy.

Part 1: Treadwear, the “how long” grade

The treadwear grade indicates a tire’s relative wear rate. The higher the number, the longer the tread should take to wear down. A control tire is assigned 100, and other tires are compared to it, so a tire graded 200 should wear twice as long as the control tire. ^[NHTSA]

It helps to know where most tires land. According to NHTSA’s figures for current tires, 15% are rated below 200, 25% are 201 to 300, 32% are 301 to 400, 20% are 401 to 500, 6% are 501 to 600, and just 2% are above 600. ^[NHTSA] So a tire in the 300s is right in the middle of the pack, and a tire above 500 is unusually long-wearing on paper.

Teacher’s note: treadwear is a comparison tool, not a warranty. How you drive, how well the tires are inflated and whether they’re rotated all change how long a tire really lasts. NHTSA notes that properly inflated tires can extend the average life of a tire by 4,700 miles. ^[NHTSA]

Part 2: Traction, the “how well it stops when wet” grade

Traction grades indicate a tire’s ability to stop on wet pavement. A higher-graded tire should stop a car on wet roads in a shorter distance than a lower-graded one. From highest to lowest, the grades are AA, A, B and C. ^[NHTSA]

Most tires sit at A: NHTSA reports 15% of current tires rated AA, 77% rated A, 7% rated B, and only four tire lines rated C. ^[NHTSA] If you drive in rain often, or simply want extra peace of mind on a slick morning commute, choosing AA is a straightforward way to favor wet stopping.

Part 3: Temperature, the “how well it handles heat” grade

Temperature grades show a tire’s resistance to heat. NHTSA explains that sustained high temperature, such as driving long distances in hot weather, can cause a tire to deteriorate, leading to blowouts and tread separation. Grades run from highest to lowest as A, B and C. ^[NHTSA] Of current tires, 62% are rated A, 34% B and 4% C. ^[NHTSA]

For Southern California drivers, this grade deserves real attention. NHTSA notes that sunlight and warmer climates contribute to tire aging, and that aging is a greater concern in the southern parts of the Sun Belt states. ^[NHTSA]

Part 4: Grades are only part of the choice

Match the tire type to your weather

All-season tires handle a variety of road conditions and have some mud and snow capability. Winter tires are more effective than all-season tires in deep snow. Summer tires are warm-weather tires not designed for temperatures below freezing or for snow and ice. All-terrain tires, mainly for four-wheel-drive vehicles, are a compromise between on-road and off-road use. ^[NHTSA]

Buy the right size

NHTSA advises buying new tires that are the same size as the vehicle’s original tires or another size the manufacturer recommends, using the owner’s manual or the Tire and Loading Information label on the driver’s side door edge or post. ^[NHTSA]

Think about fuel economy

Tires with low rolling resistance reduce energy loss. NHTSA estimates a 10% reduction in rolling resistance yields a 1–2% improvement in fuel economy, and low-rolling-resistance replacement tires can also extend the range of electric and hybrid vehicles. ^[NHTSA] For EVs specifically, NHTSA notes that because they are often heavier, they need EV-specific tires to support the weight, maximize range and reduce noise, and that low-rolling-resistance tires for conventional vehicles could have lower tread life. ^[NHTSA]

Part 5: Read the birthday, too

A tire with perfect grades can still be too old. The last four digits of the DOT Tire Identification Number show the week and year the tire was made; 0308 means the third week of 2008. The TIN may be on only one side, so look at both sides. ^[NHTSA] Some vehicle and tire manufacturers recommend replacing tires that are six to 10 years old regardless of tread. ^[NHTSA]

Part 6: Keeping the grades meaningful

The grades describe a new tire. Care keeps that performance. NHTSA recommends checking pressure on all tires, including the spare, at least once a month when cold, meaning the car hasn’t been driven for at least three hours, and using the vehicle maker’s pressure, not the number on the tire itself. ^[NHTSA] Replace tires when tread reaches 2/32 of an inch; the penny test (Lincoln’s head upside down; if you see the top of his head, it’s time) is a simple check. ^[NHTSA] In cooler months, remember that tire pressure drops as the temperature drops. ^[NHTSA]

Quick quiz

A tire graded treadwear 300 should wear how long compared with the control tire?
Answer: About three times as long, since the control tire is 100.
Which traction grade is best for wet stopping?
Answer: AA.
What do the last four digits of the TIN tell you?
Answer: The week and year the tire was made.

Calm next steps

Find the UTQG grades on your current tires and write them down.
Look up the correct size on your door-edge Tire and Loading Information label.
Check the four-digit date code on each tire, including the spare.
Decide which grade matters most for your driving (long life, wet stopping or heat).
Bring your notes when you shop and compare at least two tire lines.

Frequently asked questions

What does a traction grade of AA mean?

It is the highest traction grade. Traction grades show a tire’s ability to stop on wet pavement, from highest to lowest AA, A, B and C. ^[NHTSA]

Does a treadwear grade of 400 mean 40,000 miles?

No. Treadwear is relative: a control tire is graded 100, and a 200 tire should wear twice as long as the control tire. It is a comparison, not a mileage promise. ^[NHTSA]

Where do I find my correct tire size?

In your owner’s manual or on the Tire and Loading Information label on the driver’s side door edge or post. ^[NHTSA]

Can I use summer tires all year?

Summer tires are not designed to operate below freezing or on snow and ice. ^[NHTSA]

Sources

General education, not a diagnosis. See our disclaimer.