100Y tire service description
What does 100Y mean?
100Y: 800 kg is the nominal load-index reference and 300 km/h is the speed-symbol reference. They are not a promise of that load at that speed: application, pressure and load/speed adjustments apply.
| Load index | 100 |
|---|---|
| Maximum load | 800 kg · 1764 lb |
| Speed symbol | Y |
| Maximum speed | 300 km/h · 186 mph |
What this value can decide
100Y: 800 kg is the nominal load-index reference and 300 km/h is the speed-symbol reference. They are not a promise of that load at that speed: application, pressure and load/speed adjustments apply.
Source: UNECE / EUR-Lex — §2.28; §2.31.1–2.31.4
UN R30, linked 2008 edition, §2.31: at a vehicle maximum-speed capability of 300 km/h, the Y example uses 85% of 800 kg = 680.00 kg. This concerns the vehicle’s speed capability, not extra payload when driving slowly. Confirm the applicable approval and manufacturer data.
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.
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