The load index is a number on your tire's sidewall that tells you the maximum weight that tire can safely carry
Every tire sold in the United States has a load index printed on its sidewall, usually as a two- or three-digit number paired with a letter. That number corresponds to a specific weight capacity in pounds or kilograms. For example, a load index of 95 means that tire can safely support 1,521 pounds; a load index of 110 means 2,337 pounds. The letter that follows (usually S, T, H, V, W, Y, or Z) indicates the tire's speed rating — how fast it can go while carrying that load.
The load index matters because using a tire with an insufficient load index can cause overheating, premature wear, and blowouts. Conversely, you do not need to buy tires with a load index higher than your vehicle requires, and doing so will not improve safety or performance. The correct load index for your vehicle is determined by the vehicle manufacturer, not by the tire maker, and you can find it on a placard inside your driver's door jamb or in your owner's manual.
Key Takeaways
- The load index is a number on your tire's sidewall that corresponds to maximum weight capacity, ranging from 71 (761 pounds) to 150 (7,385 pounds) for passenger vehicles.
- Your vehicle's manufacturer specifies the minimum load index you must use; you can find this requirement on the door jamb placard or in your owner's manual.
- Replacement tires must meet or exceed the load index of the tires originally installed on your vehicle.
- Load index is separate from speed rating (the letter that follows the number) and both must be considered when choosing replacement tires.
Where to find the load index on your tire
The load index appears on the sidewall of every tire, printed as part of the tire size designation. A typical tire size might read "P215/65R15 95H" — the 95 is the load index, and the H is the speed rating. The sidewall also includes the tire's maximum pressure (in PSI), manufacturing date, tread wear warranty, and other safety information.
If you cannot read the sidewall clearly, you can also find the required load index on the vehicle placard, which is usually mounted on the inside of the driver's door or on the door frame. This placard lists the tire size and load index that the manufacturer recommends. Some vehicles have multiple placards if they came with different tire options from the factory.
How load index numbers translate to weight capacity
Load index numbers run from 71 to 150, though most passenger vehicles use indexes between 82 and 110. Each number corresponds to a specific weight in pounds. The relationship is not linear — the jumps in weight capacity vary depending on where you are in the scale. A load index increase of one number does not always mean the same pound increase.
Here are some common load indexes and their capacities for reference: a load index of 82 equals 1,047 pounds; 95 equals 1,521 pounds; 104 equals 1,984 pounds; and 110 equals 2,337 pounds. If you need the exact capacity for a specific load index, the Tire and Rim Association publishes the complete conversion table, which tire shops and manufacturers use as the standard reference.
Why load index matters for your vehicle
Your vehicle's weight, including passengers and cargo, must never exceed the load capacity of your tires. If you regularly carry heavy loads — tools, equipment, multiple passengers, or a roof rack with gear — you need to know your tires' load index to avoid overloading them. Overloaded tires generate excess heat, which accelerates rubber degradation and can cause a blowout, especially at highway speeds.
Vehicles designed to carry heavier loads, such as pickup trucks or SUVs, come with tires that have higher load indexes than sedans. A truck might require a load index of 120, while a sedan might require 95. If you replace your tires with ones that have a lower load index than the original equipment, you reduce your vehicle's safe carrying capacity and increase the risk of tire failure.
Load index versus speed rating
The letter that follows the load index is the speed rating, and it is a separate specification. Speed rating indicates the maximum speed at which the tire can safely carry its rated load. Common speed ratings for passenger vehicles are H (130 mph), V (149 mph), W (168 mph), and Y (186 mph). A tire with a high speed rating does not have a higher load capacity than one with a lower speed rating — they measure different things.
When you replace your tires, you must match or exceed both the load index and the speed rating of the original equipment. Some drivers choose tires with a higher speed rating for performance or handling characteristics, but this is a choice, not a requirement. The load index, however, is not optional — it must meet the manufacturer's minimum.
What happens if you use the wrong load index
Using a tire with a load index lower than required puts you at risk of tire failure. The tire will overheat under normal driving conditions, especially if you are carrying passengers or cargo. The rubber will degrade faster, the sidewalls may flex excessively, and the tire can fail suddenly without warning. This risk increases in hot weather and on long highway drives.
Using a tire with a load index higher than required is safe but unnecessary. A higher load index does not improve handling, fuel economy, or ride quality. It straightforward means the tire can carry more weight than your vehicle will ever place on it. Some drivers choose higher load indexes for durability or if they plan to upgrade to a heavier vehicle in the future, but this is a personal decision, not a safety requirement.
How to verify you have the correct load index
The simplest way is to compare the load index on your current tires to the requirement on your vehicle's door jamb placard. If they match or the tires exceed the requirement, you are fine. If you are buying replacement tires, show the tire shop your vehicle's placard or owner's manual, and they will select tires that meet the specification.
If you have modified your vehicle — added a heavy roof rack, upgraded to a towing package, or increased passenger capacity — you may need to reconsider your tire's load index. Some aftermarket modifications increase the vehicle's weight distribution or load capacity, which might require a higher load index than the original equipment. Consult your vehicle's manufacturer or a tire professional if you are unsure whether your current tires are still appropriate.
Frequently Asked Questions
Can I use a tire with a higher load index than my vehicle requires?
Yes. A higher load index is safe and does not harm your vehicle. It straightforward means the tire can carry more weight than your vehicle will place on it. You do not gain any performance or safety benefit, but there is no downside to using a tire with excess capacity.
What if I cannot find the load index requirement for my vehicle?
Check the placard on the inside of your driver's door or door frame — this is the most reliable source. If the placard is missing or illegible, your owner's manual will list the tire size and load index. You can also contact your vehicle's manufacturer with your vehicle identification number (VIN), and they will provide the specification.
Does load index affect fuel economy or ride quality?
Load index itself does not directly affect fuel economy or ride quality. However, tire construction, tread design, and rolling resistance — which vary among tire models — do affect these factors. Two tires with the same load index can perform very differently depending on their overall design and materials.
Can I mix tires with different load indexes on the same vehicle?
No. All four tires should have the same load index, or at minimum, all tires must meet or exceed the manufacturer's minimum requirement. Mixing tires with different load indexes can cause uneven wear, handling problems, and safety issues. Replace all four tires at the same time when possible, or at least replace them in pairs (front or rear).
What is the difference between load index and load range?
Load index is used for passenger car tires and light truck tires. Load range (A, B, C, D, E, F) is used for heavy-duty truck tires and indicates ply rating and load capacity. They serve the same purpose but use different rating systems. Passenger vehicles use load index; heavy trucks use load range.