Tire Speed Ratings
Tires & Wheels · 7 specs
Direct Answer
Tire Speed Ratings (standardized under ISO 4000-1 and ECE Regulation 30) are alphabetical index symbols indicating the maximum sustained velocity a tire can safely maintain under its rated load capacity. Ranging from Q (160 km/h / 99 mph) for dedicated winter tires to V (240 km/h), W (270 km/h), Y (300 km/h), and (Y) (>300 km/h / >186 mph) for hypercars.
Source: ECE Regulation 30 (Uniform provisions concerning tyres for motor vehicles) / ISO 4000-1 · Last reviewed Aug 28, 2026
Specs
| Standardization | ISO 4000-1 / UN ECE R30 / SAE J1561 |
| Q Rating | 160 km/h (99 mph) — Studded and studless Nordic winter tires |
| S & T Ratings | S: 180 km/h (112 mph) | T: 190 km/h (118 mph) — Standard family sedans, minivans, and all-season tires |
| H Rating (High Speed) | 210 km/h (130 mph) — Touring sedans and premium crossovers |
| V Rating | 240 km/h (149 mph) — Sport compacts and performance GT cars |
| W & Y Ratings | W: 270 km/h (168 mph) | Y: 300 km/h (186 mph) — Exotic sports cars and track-focused performance vehicles |
| (Y) In Parentheses | Speeds in excess of 300 km/h (>186 mph) — Certified individually with vehicle manufacturer for hypercars (Bugatti, Koenigsegg, Porsche GT3 RS) |
Centrifugal Force and Heat Dissipation
At 300 km/h (186 mph), a tire rotates at over 2,500 RPM, generating violent centrifugal expansion forces and extreme internal friction heat in the rubber compound and steel belts. Higher speed-rated tires (W, Y) use specialized aramid (Kevlar) or nylon zero-degree cap plies to prevent centrifugal tread delamination at extreme velocities.