Load Index Explained: What It Means for OEM Wheels and Tires
The load index is the number on a tire sidewall that tells you how much weight one tire can carry when it is inflated to the correct pressure. It matters because every wheel and tire on a vehicle has to support the vehicle’s weight, passengers, cargo, braking force, cornering load, and road impact without being overloaded.
For most drivers, the safest answer is simple: use a tire load index that meets or exceeds the original equipment specification listed on the vehicle placard or in the owner’s manual. The wheel also needs to match the vehicle by bolt pattern, diameter, width, offset, hub bore, and approved fitment. Load index is only one part of the fitment decision, but it is one of the parts you should never ignore.
What Is Load Index?
Load index is a standardized code that appears in the tire size description. In a size such as 235/55R18 100V, the number 100 is the load index. That number does not mean the tire carries one hundred pounds. It points to a load chart used across the tire industry. On that chart, a 100 load index equals 1,764 pounds per tire when the tire is properly inflated for that rating.
The index is assigned to the tire, not the wheel. Still, wheel buyers should pay attention to it because wheels and tires work as a matched system. The correct OEM wheel may be physically strong enough for the vehicle, but the tire mounted on it still has to meet the load requirement. A tire with too low of a load index can run hotter, flex more than intended, wear unevenly, or fail under weight and road stress.
Load index is different from speed rating. Load index answers the weight question. Speed rating answers the sustained speed capability question. They often appear together because the tire sidewall lists them as a service description, such as 100V, 105H, or 116T.
Why Load Index Matters on OEM Wheels
OEM wheels are designed around a specific vehicle platform. The manufacturer chooses wheel size, offset, brake clearance, tire size, load range, and inflation guidance as one package. Changing one part without checking the others can create a fitment problem that is not obvious at first glance.
A sedan, crossover, pickup, and full-size SUV may all use wheels that look similar in diameter, but their actual requirements can be very different. A passenger car tire with a lower load index may look fine on a wheel, yet it may not be suitable for a heavier SUV or truck. The opposite can also happen: a higher load tire may be safe from a load standpoint, but it may ride differently or require a pressure recommendation that needs to be checked against the vehicle specification.
For factory wheel replacement, the best starting point is the label inside the driver’s door jamb. That placard lists the original tire size and recommended cold tire pressure. Many vehicles also list load information in the owner’s manual. If a wheel is being replaced after damage, match the original wheel part number or verified OEM fitment first, then confirm the tire service description.
Common Load Index Examples
The chart below shows several common tire load index values. Always verify the exact rating for the tire you are buying, because the sidewall marking is the authority for that tire.
| Load Index | Maximum Load Per Tire | Typical Use Case |
|---|---|---|
| 91 | 1,356 lb | Many compact and midsize passenger cars |
| 94 | 1,477 lb | Midsize cars and some small crossovers |
| 98 | 1,653 lb | Crossovers, sedans, and light SUVs |
| 100 | 1,764 lb | Common on larger passenger vehicles |
| 102 | 1,874 lb | Crossovers and some minivans |
| 105 | 2,039 lb | SUVs, vans, and light truck applications |
| 110 | 2,337 lb | Heavier SUVs and truck fitments |
| 116 | 2,756 lb | Many light truck tire applications |
Those numbers are per tire. A vehicle does not simply multiply one tire rating by four and call it done. Weight is not always spread evenly. Front and rear axle loads can differ, and cargo or towing can add more demand to one axle. That is why the vehicle placard and axle rating matter.
How to Find the Correct Load Index
Start with the tire size printed on the door placard. The placard is more reliable than guessing from the tire currently installed, because previous owners sometimes mount the wrong size. Look for the tire size, service description, and cold inflation pressure. If the placard lists a size such as P235/60R18, compare the service description on the current tire with the original recommendation in the owner’s manual or a manufacturer fitment reference.
If you are moving between wheel sizes, do not rely on diameter alone. A plus-size wheel may use a lower profile tire, and that tire still needs the right load index. The new tire’s overall diameter, load rating, speed rating, and approved rim width should all be checked. A tire shop or OEM wheel specialist can confirm whether the combination is suitable for the vehicle.
For trucks and vans, also look for load range markings, such as C, D, or E, and service terms such as XL or LT. XL means extra load in passenger tire sizing. LT means light truck construction. These markings are not interchangeable labels; they point to different tire standards and inflation behavior.
Load Index vs. Wheel Load Rating
Load index belongs to the tire. Wheel load rating belongs to the wheel. Both have to be appropriate. A factory wheel made for a heavier vehicle is engineered for that vehicle’s load and use case. A wheel from a different model may share the same bolt pattern but still have the wrong offset, width, hub bore, brake clearance, or load rating.
This is one reason OEM fitment is more than a visual match. A wheel can bolt on and still be wrong. The safest replacement is the correct OEM wheel part number or a verified interchange that matches the vehicle’s engineering requirements. When Santa Ana Wheel evaluates OEM wheels, fitment accuracy comes first because the wrong wheel can create vibration, clearance, alignment, and safety issues.
Aftermarket wheels may publish a wheel load rating in pounds or kilograms. OEM wheels are normally matched through vehicle application data rather than a consumer-facing rating printed in the same way. If there is any uncertainty, do not assume that a wheel from a lighter vehicle is suitable for a heavier one.
Mistakes to Avoid
Do not replace tires with a lower load index just because the size looks close. Sidewall height and tread width are not enough to confirm a safe replacement. The service description must meet the vehicle requirement.
Do not assume all tires in the same size have the same load index. The same size can be sold in standard load, extra load, or light truck construction depending on the application. Two tires can look nearly identical while carrying different ratings.
Do not ignore inflation pressure. Load capacity is tied to correct cold inflation. Underinflation reduces the tire’s ability to carry load and increases heat buildup. Overinflation can affect ride, traction, and wear. Use the vehicle’s recommended pressure unless a tire professional provides a vehicle-specific reason to adjust it.
Do not treat wheel diameter as the only fitment rule. Bolt pattern, offset, center bore, brake clearance, rim width, and tire load index all need to work together.
What Load Index Means When Selling OEM Wheels
If you are selling used OEM wheels, load index can help identify the vehicle application, but it does not set the offer by itself. The wheel’s condition, OEM part number, size, finish, demand, and verified fitment are more important. Vehicle popularity often drives demand more than a badge alone, because shops and drivers need replacement wheels for vehicles that are commonly on the road.
Santa Ana Wheel buys OEM wheels for reuse, replacement, and remanufacturing channels. If you want an evaluation, text clear photos with the year, make, model, and your location to 949-478-2033. Photos should show the full face of the wheel, the back side if accessible, and any visible damage. If SAW makes an offer, payment is by Zelle or check.
Quick Checklist Before Buying or Mounting Tires
- Confirm the original tire size on the driver door placard.
- Match or exceed the required load index.
- Check the speed rating as a separate requirement.
- Verify the wheel is the correct OEM fitment or an approved interchange.
- Confirm wheel width is approved for the tire size.
- Use the correct cold tire pressure from the vehicle placard.
- Ask a qualified tire or wheel professional before changing size, load range, or construction type.
FAQ
Can I use a higher load index than stock?
Usually, a tire with a higher load index can be acceptable if the size, construction, speed rating, wheel width, and inflation guidance are appropriate for the vehicle. A higher number does not automatically mean the whole fitment is correct.
Can I use a lower load index if I do not carry heavy cargo?
No. The tire should meet the vehicle manufacturer’s requirement even if the vehicle is usually driven lightly loaded. Emergency braking, cornering, passengers, cargo, heat, and road impact all matter.
Is load index the same as load range?
No. Load index is a numeric tire rating. Load range is a construction category often used with light truck tires. Both relate to carrying weight, but they are not the same label.
Does an OEM wheel determine the tire load index?
The tire carries the load index marking, but the OEM wheel and tire must be selected as a correct package for the vehicle. The wheel fitment and tire service description both need to match the application.
