The tire load index is a coded number that tells you the tire's load-carrying capacity when used according to its specification.
Where to find it
The load index appears in the tire size and service description on the sidewall. For example, in a marking such as 235/55R19 105V, the number 105 is the load index and the letter V is the speed rating.
The correct requirement for your vehicle is usually listed in the owner's manual and on the Tire and Loading Information label.
What the number means
The load index is not the weight itself. It maps to a load capacity in a standardized table. A higher number generally means the tire can carry more weight, but only when used at the proper pressure and within the tire's specification.
Why it matters for replacement tires
Replacement tires should meet or exceed the vehicle manufacturer's required load index. Using a tire with too low a load rating can reduce safety margin, especially when the vehicle is full of passengers, cargo or towing load.
Load index and tire pressure
Load capacity depends on pressure and tire construction. A strong load index does not help if the tire is underinflated. That is why TPMS and manual pressure checks still matter.
Load index is not speed rating
Load index and speed rating are different markings. The load index relates to weight capacity. The speed rating relates to sustained speed capability under defined conditions.
Related terms
Sources
- NHTSA TireWise - Tire buying, maintenance and labeling
- 49 CFR 571.110 - Tire selection and rims
- Bridgestone - Tire load index
Feature names, connector support, diagnostic behavior and EV specifications can vary by model year, trim, software version and market. Always verify the exact vehicle documentation before buying, repairing or relying on a feature.