Load index and speed rating explained

Those numbers and letters after the size code are not optional fine print — they describe capacity and rated capability.

Where they appear

On a typical sidewall service description you might see something like 225/65R17 102H. Here, 102 is the load index and H is the speed rating symbol. Always confirm the exact marking on the tire you buy.

Load index (plain English)

Load index maps to a maximum load capacity per tire at a specified inflation condition defined by industry standards. A higher index generally means higher capacity — but you still must meet your vehicle’s requirements and set pressure correctly.

Do not choose a lower load index than OEM specifies for your vehicle.
Replacing only two tires? Match load capability and follow installer guidance on axle placement.
Heavy vehicles, towing packages, and some EV trims may require XL / reinforced constructions — check OEM docs.

Speed rating (plain English)

Speed symbols (such as T, H, V, W) correspond to rated speeds under standardized conditions. They are not a license to drive at those speeds, and real-world limits include road law, tire condition, inflation, and vehicle capability.

Symbol (examples)	Editorial note
S, T	Common on many touring / all-season passenger applications
H, V	Often seen on higher-performance touring fitments
W, Y	Typically associated with higher-rated performance tires

Mixing speed ratings across an axle is generally discouraged; follow OEM and installer guidance.

TPMS and electronics

Changing wheels or tire constructions can interact with tire-pressure monitoring and other systems. Plan sensor service with your installer.