What Your Tire's Load Rating Means and Why It Matters

The load rating tells you the maximum weight each tire can safely carry

Every tire has a load rating — a number that represents the heaviest weight that single tire can support at its maximum air pressure. This number appears on the tire's sidewall, printed as a two or three-digit code. It is not the weight your car weighs; it is the weight one tire must handle on its own.

Load ratings matter because overloading a tire causes it to flex too much, generate excess heat, and fail suddenly. A blowout at highway speed is dangerous and expensive. Matching your tires to your vehicle's actual weight — including passengers, cargo, and equipment — keeps you safe and makes your tires last longer.

The rating system uses a load index, which is a number between 71 and 126 on most passenger tires. Each number corresponds to a specific weight capacity in pounds. A load index of 91, for example, means that tire can carry 1,565 pounds at full pressure. A load index of 100 means 1,764 pounds. The higher the number, the more weight the tire can handle.

Key Takeaways

• The load index is a two or three-digit number on your tire's sidewall that tells you the maximum weight one tire can safely carry.
• You must match your tires to your vehicle's Gross Vehicle Weight Rating (GVWR), which is listed on a sticker inside your driver's door jamb.
• Divide your vehicle's GVWR by four to find the minimum load index each tire needs; always round up if the number is not exact.
• Overloaded tires wear faster, run hotter, and can fail suddenly, even if your vehicle feels fine to drive.
• Towing and roof racks add weight to your vehicle, so you may need higher-rated tires if you regularly carry heavy loads.

How to find your vehicle's weight requirement

Your vehicle has a Gross Vehicle Weight Rating (GVWR) — the maximum total weight your car, truck, or SUV can safely carry when fully loaded with passengers, cargo, fuel, and equipment. This number is not the same as the vehicle's curb weight (what it weighs empty). The GVWR is printed on a label inside your driver's door jamb, usually on the door edge or the frame near the latch.

To find the load index you need, divide your GVWR by four. If your GVWR is 4,800 pounds, each tire must have a load index that supports at least 1,200 pounds. Look up that weight on a load index chart to find the corresponding number. If the math gives you 1,200 pounds and the closest load index supports 1,190 pounds, you must round up to the next index — never down.

Your vehicle's original tires were chosen to meet or exceed this requirement. If you replace them with tires that have a lower load index, you are reducing your vehicle's safe carrying capacity, even if the tires fit the wheel size.

Where to find the load index on your tire

The load index appears on the tire's sidewall as part of the tire size code. A typical sidewall marking looks like this: 225/65R17 102H. The "102" is the load index; the "H" is the speed rating. The load index always comes before the speed rating in this sequence.

If you cannot read the sidewall clearly, the load index is also printed on your vehicle's door jamb label, usually listed as a number next to the tire size. You can also find it in your owner's manual or on the manufacturer's website by entering your vehicle's year, make, and model.

When you buy replacement tires, the salesperson or shop will confirm that the load index matches your vehicle's requirement. Do not assume all tires in your size have the same load index — they do not. A 225/65R17 tire might have a load index of 100, 102, or 104 depending on the brand and model.

Load rating versus speed rating

The load index and speed rating are two separate pieces of information that both appear on your tire's sidewall. The load index tells you weight capacity; the speed rating tells you the maximum speed the tire can sustain safely. Both matter, but they measure different things.

A tire with a high load index but a low speed rating is safe for heavy weight at low speeds. A tire with a high speed rating but a low load index is safe for high speeds but cannot carry as much weight. Your replacement tires should meet or exceed both your vehicle's load index requirement and its speed rating requirement. Your owner's manual or door jamb label lists both.

What happens when you overload a tire

An overloaded tire flexes more than it is designed to, which generates heat inside the tire faster than the tire can shed it. This heat weakens the tire's internal structure and can cause the sidewall or tread to separate from the carcass — the rubber layers underneath. A separated tire loses air pressure suddenly and can fail completely while you are driving.

Overloading also accelerates wear. An overloaded tire wears down faster and unevenly, shortening its lifespan and reducing traction. You may not notice the problem until the tire fails, because the vehicle may feel normal to drive even when the tire is dangerously stressed.

Towing a trailer, carrying a roof rack, or loading your trunk with cargo all add weight to your vehicle. If you regularly tow or carry heavy loads, you may need tires with a higher load index than your vehicle's minimum requirement. Check your vehicle's manual for towing capacity and the weight of any equipment you use regularly.

Load rating for trucks and SUVs

Trucks and SUVs often have higher GVWRs than sedans, which means they need tires with higher load indexes. A full-size pickup truck might have a GVWR of 5,500 pounds or more, requiring tires with a load index of 110 or higher. An SUV used for towing may need even higher-rated tires.

If you own a truck or SUV and plan to tow, haul, or carry heavy loads regularly, talk to a tire shop about your actual usage. They can recommend tires that handle your typical load plus a safety margin. Undersized or underrated tires on a truck are a common cause of tire failure and can void your vehicle's warranty.

Checking your tires against your vehicle's needs

To verify that your current tires are adequate, find your vehicle's GVWR on the door jamb label. Divide by four and note the minimum load index required. Then look at your tire's sidewall and find the load index number. Compare the two: your tire's load index must be equal to or greater than the minimum you calculated.

If your tires fall short, they are not safe for your vehicle's maximum capacity, even if they are the right size and fit properly. Replace them with tires that meet the load requirement before you load your vehicle to capacity or tow anything heavy.

When you buy new tires, tell the shop your vehicle's GVWR and your typical usage. They will recommend tires that meet the requirement and are appropriate for how you actually drive. This takes the guesswork out of the decision and ensures you get tires that are safe for your vehicle.

Frequently Asked Questions

Can I use a tire with a higher load index than my vehicle needs?

Yes. A higher load index is always safe; it simply means the tire can handle more weight than your vehicle requires. Many people choose higher-rated tires for durability or to accommodate future towing or cargo needs. The tire must still be the correct size and speed rating for your vehicle.

What if my tire size has different load indexes available?

Different brands and models of the same tire size can have different load indexes. When shopping, check the sidewall or ask the shop for the load index of each option. Choose one that meets or exceeds your vehicle's minimum requirement. Do not assume all tires in your size are the same.

Does tire pressure affect the load rating?

Yes. The load rating assumes the tire is inflated to its maximum pressure, which is printed on the tire's sidewall. If you underinflate your tires, their load capacity decreases. Always maintain the pressure recommended on your vehicle's door jamb label, not the maximum pressure on the tire itself.

Do all four tires need the same load index?

Yes. All four tires on your vehicle should have the same load index to ensure even weight distribution and handling. Mixing load indexes can cause uneven wear and handling problems. Replace all four tires at the same time if possible, or at least replace them in pairs on the same axle.

What is the difference between load index and load range?

Load index is used for passenger tires and is a number between 71 and 126. Load range is used for light truck tires and is a letter (C, D, E, F) that indicates ply rating and load capacity. Check your vehicle's manual to see which system applies to your tires.