Passenger-vehicle tyre fundamentals — NHTSA UTQG consumer guide

• Source / publisher: NHTSA (US National Highway Traffic Safety Administration — annual consumer guide); EU tyre-label regulation references
• Type: guide + standard (official consumer guide + regulatory grading framework)
• Topics: UTQG grades decoded (treadwear comparative index, traction AA–C wet-braking, temperature A–C heat resistance — and the caveats: course vs real-world, straight-line only), sidewall markings (size notation, load index, speed symbol, DOT TIN/date code, ply construction, max load/ pressure), federal safety baselines, what to check when buying; EU label scheme (wet grip, rolling resistance, noise classes — Reg. 2020/740); seasonal/all-weather tyre distinctions
• Vehicle scope: car (passenger tyres)
• Region: US (UTQG US-specific; EU label is the other major scheme)
• Language: en
• Link: rosap.ntl.bts.gov | License/access: public (government)
• Notes:
  • NHTSA republishes annually (June) — cite the current year; 2024 edition linked.
  • The legal standard is 49 CFR 575.104: law.cornell.edu
  • EU tyre label (3-icon scheme familiar from retail): Reg. (EU) 2020/740 — label database at eprel.ec.europa.eu.
  • SA context: no labelling scheme — SA buyers see EU labels on imported tyres; load index/speed rating literacy is the transferable skill.
  • Pairs with the heavy-truck tyre guides (TMC radial tyre conditions) — this is the passenger-side counterpart.