100Y tire service description
What does 100Y mean?
100Y combines a load index and a speed symbol. In this seed page it means 800 kg maximum load per tire and 300 km/h (186 mph) maximum speed under the standard test conditions for that rating.
| Load index | 100 |
|---|---|
| Maximum load | 800 kg · 1764 lb |
| Speed symbol | Y |
| Maximum speed | 300 km/h · 186 mph |
Always meet or exceed the vehicle placard/manual requirement for load and speed rating.
How to use a service description
The service description follows the size marking, for example 225/45R17 91V.
The number is the load index and the letter is the speed symbol. Replacement tires should
normally meet or exceed both values specified by the vehicle manufacturer.
The rating is not a promise that every tire is suitable for every vehicle. Pressure, axle load, wheel size, construction, certification and local rules still matter.
Related charts
Seasonal check
Planning a long summer drive?
Use the budget and running-cost tools before a trip, especially if the current tires are worn or the replacement size changes diameter.
- Technical check
- 2026-06-28
- Content updated
- 2026-06-28
What changed
- Added curated service-description seed pages from load-index and speed-symbol data.