Tire load index

Goodyear says the load index appears on the sidewall after the tire size. Continental explains that the number is a code, not a weight in pounds or kilograms.

Use the load index tool or chart to find maximum load in lbs and kg per tire. Westlake’s published table lists index 91 as 1,356 lbs (615 kg) and index 116 as 2,756 lbs (1,250 kg). Goodyear says a higher index means greater load-carrying capacity.

Read the load index alongside the speed rating, not as an independent limit. Toyo’s definition ties load capacity to the speed symbol under the manufacturer’s specified service conditions.

Goodyear says light-truck tires show separate load indexes for single and dual use. The first applies to a tire in single service; the second applies to each tire in dual service.

Nitto lists the Ridge Grappler LT275/65R20 with service description 126/123Q and load range E. Westlake’s index table maps 126 to 3,748 lbs (1,700 kg) per tire in single service and 123 to 3,417 lbs (1,550 kg) per tire in dual service.

The dual value is per tire, not the combined capacity of the pair. 49 CFR 571.119 (FMVSS No. 119) requires tires rated for single and dual use to show separate maximum loads, each with its cold inflation pressure.

Michelin says XL means Extra Load: reinforced construction allows higher loads than standard tires of the same size when inflated to higher pressures. Michelin also says vehicles with factory XL tires need XL-rated replacements because standard-load tires of the same size lack the required capacity.

Nitto lists the P-metric 275/65R20 Ridge Grappler as SL, with service description 116T and a maximum load of 2,756 lbs. Its LT275/65R20 version is load range E, with a maker-listed maximum load of 3,750 lbs. These are ratings for those specific versions, not a universal conversion between SL and LT.

A load range marking does not replace the load index or the tire’s load rating. For inflation pressure, see the tire and loading placard on the driver's door jamb.

49 CFR 571.139 (FMVSS No. 139) requires the sidewall to show maximum load and, for LT tires, the load range letter. It also requires the maximum permissible inflation pressure marking; that is a limit, not the pressure to run.

For trucks, SUVs and trailers, 49 CFR 571.110 (FMVSS No. 110) requires the tire load ratings on an axle to total at least that axle’s GAWR on the certification label. For passenger cars, the regulation says maximum vehicle load on a tire cannot exceed its marked load rating.

Michelin says replacement load ratings must meet or exceed the vehicle manufacturer’s specification and warns against a lower load index. 49 CFR 571.110 (FMVSS No. 110) places the tire and loading placard on the driver’s side B-pillar, at the door jamb.