100Y tyre 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 tyre and 300 km/h (186 mph) maximum speed under the standard test conditions for that rating.

FAQ

What does 100Y mean?
100Y combines a load index and a speed symbol. In this seed page it means 800 kg maximum load per tyre and 300 km/h (186 mph) maximum speed under the standard test conditions for that rating.
What should I verify before using this information?
Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.
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 tyres should normally meet or exceed both values specified by the vehicle manufacturer.

The rating is not a promise that every tyre 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 tyres are worn or the replacement size changes diameter.

Estimate tyre budget
Last reviewed: 2026-06-28
What changed
  • Added curated service-description seed pages from load-index and speed-symbol data.