Guides

Two explainers for the data on this site. Both stick to the regulations and to NHTSA's own descriptions.

• What UTQG treadwear, traction, and temperature grades mean
• How to read a DOT tire identification number

The data sources page describes the files, including brand-string errors, plant status, and which tires UTQG does not cover. If a light-truck, winter, or temporary spare tire is missing from the ratings, start with why a tire may be absent.