Did you know that tire manufacturers rate every tire type with a load index? Did you know they stamp the load index on the side of each tire? The load index (sometimes called the weight index) represents the maximum amount of weight each tire is rated to carry, and it is a critical aspect of your tires: If you are replacing your tires and buy ones with a lower load index, you risk a blowout. Knowing your tire load index is important for proper vehicle maintenance. Learn how to find your tire load index and decode it with our handy tire load index chart explained below.

What Is A Tire Load Index?

If you know how to read the letters and numbers on tires, you already know that the first number in your tire size is your tire width in millimeters. You already know the second number (after the first slash) is the aspect ratio between your tire’s width and sidewall height. And you know the third number (usually after the letter R) is your rim diameter in inches.

You may not have known that the number after the rim diameter (and the second slash) is not a measurement at all: it is a code. This two-digit or three-digit code represents your tire’s load index. The higher this number, the higher the weight each tire is rated to carry.

For example:

• A tire with a size of “275/55R20/113T” has a load index of 113
• A tire with a size of “225/65R17/102H” has a load index of 102
•  A tire with a size of “205/65R15/94V” has a load index of 94

Most passenger cars and light trucks come from the factory on tires with load indexes between 70 and 126. These tires are rated to carry anywhere from 739 pounds to 3,748 pounds–each. These numbers do not represent weight or tons, they are a code and require a tire load index chart to decode.

Remember, the total load index of your set of tires is not necessarily the same as your vehicle’s maximum load. There are many aspects of your car that can fail before your tires. The load index on your tire is simply the max tire weight that one tire is rated for.

Tire Load Index Chart

Changing Your Tire Load Index

It is not a great idea to replace your tires with aftermarket tires that have a lower load index. If the total weight of your vehicle and load exceeds the max tire weight for your set of tires, you risk a blowout. Likewise, if you put more weight on the front or rear tires and exceed their individual weight ratings, you also risk a blowout. And note that if you exceed your tires’ speed rating, you may suffer a blowout without even exceeding your max tire weight.

You can always upgrade your tires to aftermarket tires with a higher load index. Your new tires will be suited to carry more weight. But certain tires with a high load index are louder than stock tires or make for a stiffer ride than stock tires. Be sure to do your research before upgrading your load index.

Is Your Max Tire Weight Approaching Your Load Index?

Do you often carry heavy loads or trailer heavy loads with your vehicle? Do you worry you are approaching your tire load index? You can add together the weight each of your tires is rated for to calculate your overall max tire weight. Subtract your vehicle weight and you will have some idea how much load your tires can carry. Remember, unless the load is balanced between all your tires equally, this weight may be much lower.

Make certain to care for your tires: First, correctly rotate your tires, regularly. Second, store your seasonal tires properly. Don’t push the limit on used tires with worn rubber. And double-check that your tires are not involved in the Continental tire recall, or the Bridgestone and Firestone tire recalls.

Sources: Tire Rack and Driving Line