Why treadwear can differ by size
Source: NHTSA UTQG tire ratings, last updated November 9, 2026 (UTC).
UTQG grades are assigned by the manufacturer under 49 CFR 575.104. NHTSA's file stores a row for each size series it published. The treadwear number or the traction letter on that row can differ from another size of the same line. Tire makers often assign the grade from a test of a representative size. The grade molded on the sidewall of the tire you buy is the grade for that tire. A single number in a generic listing can hide the range NHTSA lists. Treadwear is a relative grade from a government test course, not miles. Grades from different brands are only loosely comparable.
Open the ratings table. Compare tire lines. What the grades mean. What treadwear numbers mean.
How many lines in this file
The counts below group the committed ratings by the brand string and line name on this site, after letter case, spacing, and brand punctuation are normalized. A size row with treadwear 0, no treadwear number, a treadwear value that is not a whole number, or a traction or temperature letter outside the usual grades is left out. Those rows stay on the tire-line page. The usual traction letters are AA, A, B, and C. The usual temperature letters are A, B, and C. A line name stored under more than one brand is counted under each brand string separately. That match is not evidence the tires are the same product. Repeated line names. Grades that vary by size.
| What NHTSA lists | Tire lines |
|---|---|
| More than one treadwear number above 0 | 465 |
| More than one traction grade | 190 |
| Grade varies by size (either of those) | 539 |
Lines in this pull
Each row was found by looking up the line name in this pull. A name that is not in the file, or that has one treadwear number and one traction grade, is not listed. The range is the values on that line's size rows after flagged rows are left out.
| Tire line | Treadwear NHTSA lists | Traction NHTSA lists | Size rows |
|---|---|---|---|
| Bridgestone ECOPIA EP150 | 200–880 | A and B | 8 |
| Hankook Dynapro HP2 (OE) | 360–820 | A | 16 |
| Toyo VERSADO LX | 360–700 | AA and A | 3 |
| Toyo TOUREVO LS | 360–700 | AA and A | 3 |
Open this list in the table: size-specific grades. Compare two to four tire lines.
What to read on the tire
The grade molded on the sidewall is the grade for the tire you buy. A listing that prints one treadwear number for the whole line is not a substitute for that sidewall, and it is not a distance the tire will travel. The tire-line page keeps every size series NHTSA published and, when treadwear or traction has more than one value, shows the count of size rows for each value.
What UTQG treadwear, traction, and temperature mean. Why a tire may have no UTQG rating. Data sources.
Questions
Why do different sizes of the same tire list different treadwear?
NHTSA lists a treadwear number on each size row. Tire makers often assign that grade from a test of a representative size, and another size of the same line can carry a different number. The grade molded on the sidewall of the tire you buy is the grade for that tire.
Does a different treadwear number say how far the tire will travel?
No. Treadwear is a relative grade under 49 CFR 575.104, from a government test course, not miles. NHTSA's file does not turn that number into a distance.
Which grade applies to the tire I buy?
The grade molded on the sidewall of the tire you buy is the grade for that tire. A single number in a generic listing can hide the range NHTSA lists across sizes of the line.