What Is Load Index & Weight Rating On Tires

Understanding how much weight your vehicle can carry is extremely important, especially if you’re regularly hauling large loads. To better assess how much you can carry, you need to know a few different terms.

What we’re going to talk about today is load index and load range (both of which you can find on the sidewall of your tires), as well as weight rating. Weight rating is not a term we use often in relation to tires, but it’s one that’s commonly used to describe the maximum load a vehicle can carry.

We’ll start by talking tires, then we’ll talk about the overall weight rating of your vehicle. Let’s get started.

What is load index?

The load index can be found on the sidewall of your tire - it’s a two or three digit number, followed by a letter. The letter is your vehicle’s speed rating - not relevant to this article, but nice to know about.

This number tells you how much weight a tire can handle. Each number corresponds to a maximum weight. See the chart below:

It’s important to note that the load index tells you how much weight one wheel can handle - this means that a full set of tires can carry 4 times the load index of a single tire. 

What is load range?

Load range is related to the load index, but the information it gives us is quite different. A tire’s load range will tell you the maximum air pressure your tire can take. It’s also an indicator of the general “toughness” of a tire. Load ranges are associated with load indexes because, generally, the tougher a tire is (and the more air pressure it can sustain), the more weight it can handle.

Your tire’s load range is represented by a letter - we won’t get too deeply into it here, though, because if you’re focused on weight, the load index is the primary indicator you should be paying attention to.

The Gross Vehicle Weight Rating

Now you know how much weight your tires can handle - but how much weight can your vehicle handle? That’s where the Gross Vehicle Weight Rating (GVWR) can come in handy.

The GVWR is determined by the manufacturer, using stock parts. It tells you how much weight your vehicle can handle, including the curb weight of the vehicle (that’s the vehicle’s weight with nothing inside it). 

Even if your load index means your tires can carry more weight than the GVWR, you should almost never exceed the GVWR. You don’t know which parts of your vehicle might collapse under too much weight. Of course, if you’ve replaced all of the parts of your vehicle, and you know how much weight every individual part can take, you might be okay. But if you’re reading this article, it’s very likely that you don’t know about load ratings, and should stick with keeping your vehicle well below the GVWR.

While tires may not increase the maximum load capacity of your vehicle alone, they can do a whole lot to improve your ride. Learn more about what new tires can do for you.