The Tire Load Index is a numeric code molded into the sidewall of every tire that shows how much weight a single tire can safely support. Many drivers never notice it, yet it plays a direct role in safety, handling, and choosing replacement tires.
This guide explains what the number means, how it is determined, how it differs from tire pressure and speed rating, and how to confirm that the tires on your vehicle meet the manufacturer’s requirements before you buy or rotate them.
Where to Find the Load Index on Your Tire Sidewall
Every passenger and light truck tire carries a size designation on its sidewall, usually printed in a sequence such as P225/60R17 98H. The two-digit or three-digit number that follows the width, aspect ratio and construction letters is the load index. It sits alongside a letter that represents the speed rating, which is a separate piece of information.
Reading the sidewall takes only a moment. Look for the cluster of characters near the size markings, often beside the words Load Index or simply a number between about 70 and 120. Because the label is molded into rubber, it may appear faint on older or heavily worn tires, so a flashlight can help.
The load index is not the same thing as the maximum load printed in pounds or kilograms on the sidewall. The load index is a code that corresponds to a table of values, and the table is standardized so manufacturers worldwide use the same reference. Understanding this code lets you compare tires from different brands on an equal footing.
If you cannot read the sidewall clearly, the tire placard on the driver’s door jamb or the owner’s manual lists the original equipment size and load index for your vehicle. A tire shop can also look up the specification from the tire’s size and construction details.
What the Load Index Number Actually Represents
The load index is a standardized figure that represents the maximum weight a single tire can carry when it is inflated to a specified pressure and operated under defined conditions.
Engineers establish these values through laboratory testing that considers the tire’s structure, materials and internal construction. The number is not a measurement of pounds directly but a reference to a published chart.
A higher number indicates that the tire can support more weight. A tire rated at 98 can carry more than one rated at 91, and the difference between neighboring numbers is meaningful.
Load capacity depends on pressure. A tire can only carry its rated load when it is inflated to the pressure set for that load. Underinflation reduces the effective capacity and increases heat buildup, which can damage the tire.
The load index applies to each tire individually. The total weight a vehicle can carry is shared among all tires, and the vehicle manufacturer calculates the requirement for each axle. Knowing the number on one tire does not tell you the full capacity of the vehicle, but it does tell you whether that single tire is suitable for its position.
Common Load Index Values and What Each Range Suggests
Load index numbers appear across a wide range, and drivers often see a handful of values repeatedly on passenger vehicles and light trucks. The table below is illustrative only and does not replace the standardized chart or your vehicle’s specification.
- Index values in the low 70s to mid 80s often appear on compact and small passenger tires.
- Values in the upper 80s to mid 90s are common on midsize sedans, crossovers and family vehicles.
- Values around 100 and above are typical of larger SUVs, light trucks and vehicles designed to carry heavier loads.
- Load index numbers do not indicate quality, comfort or durability on their own, so a higher number is not automatically better.
- Always match or exceed the vehicle’s original specification, and never choose a lower index than the manufacturer requires.
These ranges are general observations rather than fixed rules. Two tires with the same index can differ in tread design, ride comfort and wear life, so the number should be one factor among several. Your vehicle’s specification is the authoritative reference for what index you need, and it may vary by trim level, option package or axle position.
Load Index Compared With Speed Rating and Pressure Ratings
The load index is often read together with the speed rating, which appears as a letter immediately after the index number, such as H or V.
The speed rating tells you the maximum speed at which the tire is designed to operate under specified conditions. It is a separate specification, and a tire must meet both the load index and speed rating required by the vehicle.
Tire pressure ratings are also printed on the sidewall, usually as a maximum pressure in pounds per square inch or kilopascals. This figure is the highest pressure the tire can safely hold, and it is not the same as the recommended cold inflation pressure for your vehicle.
The recommended pressure is listed on the door placard and should be used for daily driving and for matching the load index.
Mixing up these ratings is a common source of confusion. A tire may have a high maximum pressure and a high speed rating yet a lower load index than your vehicle requires. When you compare replacement options, check all three values, and treat the vehicle manufacturer’s specification as the baseline.
Using the Load Index When You Replace or Upgrade Tires
Choosing replacement tires involves more than matching the size on the sidewall. The load index is one of the most important specifications to confirm, because it determines whether a tire can safely carry the weight placed on its axle. Taking a systematic approach helps prevent costly mistakes and protects handling and braking performance.
Matching the Original Equipment Specification
Start by confirming the original equipment size and load index listed in your owner’s manual or on the tire placard. Manufacturers usually specify a load index that meets or exceeds the minimum needed for the vehicle’s gross axle weight rating, so this number is your starting point for any replacement.
When buying tires, compare the index on each option with the original. Many drivers choose a higher index for added margin, particularly when carrying heavy loads or towing, provided the new tire fits the wheel and the change is compatible with the vehicle. Ask a qualified tire professional to confirm any change before you install it.
Avoiding the Risk of Choosing a Lower Index
A lower load index is the most significant mistake to avoid. A tire with a smaller index may not support the weight placed on it, especially when the vehicle is fully loaded, on a hot day, or traveling at highway speeds. Underrated tires can overheat, lose structural integrity and fail, which poses a serious safety risk.
Lower index tires may also change the vehicle’s handling, ride height and speedometer reading if the overall diameter differs. Because these effects can compound, always verify that a replacement meets or exceeds the specification, and document the change in your maintenance records.
Confirming Compatibility Before Installation
Before installation, confirm that the tire’s size, load index and speed rating match the requirement for each position on the vehicle. Some vehicles use different sizes front and rear, and this must be respected. Mixing tires with different indexes on the same axle is generally not recommended, since uneven capacity can affect stability.
A qualified technician should also check that the wheels are rated for the tire’s load and that the tire is correctly mounted and balanced. Reviewing these details with a professional is the most reliable way to ensure the new set performs as the manufacturer intended.
How Vehicle Load, Towing and Accessories Affect Tire Capacity
Passengers, cargo and accessories all add to the weight carried by your tires. A vehicle filled with people and luggage can approach its design limits, and the axle loads may be higher than when the vehicle is driven alone. The load index exists to make sure each tire can handle its share of this weight, but the margin is finite.
Towing places additional stress on the rear tires of many vehicles and can also affect the front axle through tongue weight. The vehicle manufacturer provides towing ratings and may specify tire requirements for towing. Following those instructions and checking the placard for loaded pressures helps keep the tires within their rated capacity.
Accessories such as roof racks, cargo boxes, bull bars and heavy aftermarket wheels can alter the load distribution and the effective capacity needed.
Adding weight should be considered carefully, and the vehicle’s gross and axle weight ratings should be respected. If you are unsure whether your setup is within limits, a weighing service or a qualified technician can help you assess the situation.
Checking Load Capacity Safely at Home and at the Shop
You can perform several safe checks at home without special equipment. Read the load index and speed rating on each tire, compare them with the placard and the owner’s manual, and confirm that the tires on the vehicle match the specification.
Note any tire that is damaged, bulging or unevenly worn, since these conditions can reduce capacity regardless of the index.
Check inflation pressure when the tires are cold, using a reliable gauge, and inflate to the placard value. Pressure affects how much weight a tire can carry, so keeping it correct is one of the most effective steps you can take to protect the rated capacity. Recheck pressure regularly, since temperature changes can shift it.
At a tire shop, ask the technician to confirm the load index of any replacement and to explain how it compares with the original specification. A reputable shop will show the rating on the tire and provide the specification in writing. Keep records of the purchase and any changes to size or index for future reference.
Signs That Tires May Be Overloaded or Undersized
Overloaded or undersized tires often show signs that can be noticed during routine driving and inspection. Paying attention to these indicators helps you act before a problem becomes serious. The following observations are worth checking, especially after carrying heavy loads or changing tires.
- Excessive heat or a noticeably warm tire after a short drive can indicate that the tire is working beyond its capacity.
- Bulges, bubbles or unusual sidewall shape suggest structural stress and call for immediate professional inspection.
- Uneven wear across the tread, particularly on the shoulders, may reflect incorrect pressure or inadequate capacity.
- A vehicle that sags, handles unpredictably or feels unstable when loaded may be carrying more weight than the tires support.
- Any tire that has been repeatedly underinflated or overloaded should be inspected by a qualified technician before continued use.
If you notice any of these conditions, reduce the load, check the pressure and arrange an inspection. Do not continue driving on a tire that appears damaged. A technician can determine whether the tire can be safely used, must be replaced, or requires a change in load or inflation to remain within its rating.
Planning Your Next Tire Purchase With Confidence
When you plan your next tire purchase, begin by collecting the information your vehicle requires. Note the original size, load index and speed rating from the owner’s manual and tire placard, and record your typical loads, towing needs and driving conditions. This baseline lets you evaluate options quickly and avoid choices that fall below the requirement.
Keep a simple record of your tire specifications, purchase dates and inspection results. Documentation helps you track wear and supports any warranty or service questions you may have later. It also makes it easier to compare future replacements and to confirm that changes meet the manufacturer’s guidance.
Schedule regular checks of pressure, condition and rotation as directed by your owner’s manual. Ask a qualified tire professional to review your setup periodically, especially if you change how you use the vehicle. Staying attentive to the load index and related ratings helps keep your tires working safely for the life of the set.