Tire Load Index and Speed Rating Explained

What those letters and numbers after the tire size actually mean — and why they matter for safety.

What Is Tire Load Index?

The load index is a number (usually 70–126) that tells you the maximum weight each tire can safely support when properly inflated. It appears on the sidewall right after the tire size — for example, in 225/65R17 102H, the load index is 102, which corresponds to 1,874 lbs per tire.

Load IndexMax Load (lbs)Common Use
851,135Small sedans
951,521Mid-size sedans/crossovers
1021,874SUVs, minivans
1102,337Light trucks, full-size SUVs
1203,086Heavy-duty trucks

Rule: Never install tires with a load index lower than what your vehicle manufacturer specifies. Going higher is fine.

What Is Speed Rating?

The speed rating is the letter after the load index. It indicates the maximum sustained speed the tire is designed to handle safely.

RatingMax SpeedTypical Vehicle
S112 mphFamily sedans, minivans
T118 mphStandard cars, light trucks
H130 mphSport sedans, coupes
V149 mphSports cars, performance SUVs
W168 mphHigh-performance vehicles
Y186 mphExotic/supercar

Speed rating does not mean you should drive at that speed — it means the tire can handle sustained heat at that speed. A tire rated H is also perfectly fine for normal highway driving.

Where to Find Your Required Ratings

Check the sticker inside your driver-side door jamb or your owner's manual. It lists the exact size, load index, and speed rating your car was designed for. You can go up in speed rating, but never down.

XL and Extra Load Tires

Some tires are marked XL or Extra Load. These are built with reinforced sidewalls and can carry more weight than a standard tire of the same size. If your vehicle requires XL tires, you must replace them with XL tires.

Frequently Asked Questions

Can I use a higher load index than required?

Yes. A higher load index means more capacity, which is always safe. Never go lower than what your vehicle requires.

Do all four tires need the same speed rating?

Ideally yes. If you mix ratings, the lowest-rated tire limits your safe speed. Always match or exceed the OEM specification.

What happens if I use tires with a lower speed rating?

The tire may overheat at high speeds, increasing the risk of a blowout. Always meet or exceed the manufacturer's required speed rating.

What does 102H mean on a tire?

102 is the load index (1,874 lbs max per tire) and H is the speed rating (130 mph max sustained speed).