Tire load index numbers show the maximum weight one tire can carry when it is inflated to its rated pressure.
If you’ve ever stared at the numbers and letters on a tire sidewall and felt a bit lost, you’re not alone. Load index is one of those details people skip past until they need new tires, add cargo, or spot a mismatch on the car. Then it suddenly matters a lot.
A tire can match your wheel size and still be wrong for the vehicle if its load rating is too low. That’s the part many drivers miss. The load index tells you how much weight each tire is built to carry, and that figure needs to line up with the vehicle’s needs, not just the rim diameter.
Once you know where to look, the number is easy to spot and easier to use. It sits near the end of the tire size code, right before the speed rating letter. Read it right, and shopping for replacements gets a lot less confusing.
Tire Load Index Numbers On The Sidewall
The load index is a coded number that matches a set weight from an industry chart. A higher number means the tire can carry more weight. It is not a random mark, and it is not a guess from the tire shop.
Say you see a sidewall marked 225/45R17 94V. The “94” is the load index. The “V” after it is the speed rating. In that case, each tire is rated to carry 1,477 pounds when used under its rated conditions. Four tires at that rating add up fast, but the car’s own weight, passengers, cargo, and tongue weight all eat into that total.
Where To Find The Number
You’ll spot the load index in the service description area of the sidewall. It normally appears after the tire size and before the speed letter.
- 205/55R16 91H — load index is 91
- 235/65R17 104T — load index is 104
- 275/40R20 106Y — load index is 106
If the sidewall has more markings like XL, SL, or LT, those marks still do not replace the index number. They add context, but the load index is still the number you match when comparing tires.
What The Load Index Does Not Tell You
This number gets mixed up with other tire markings all the time. It does not tell you tread life. It does not tell you ride comfort. It also does not mean you can inflate the tire to any pressure and carry the full rated weight.
Load index works with inflation pressure. A tire only reaches its rated carrying ability under the conditions tied to that rating. That’s one reason the door-jamb placard matters so much. The car maker picked the tire size, pressure, and minimum load level as a package.
Why This Number Matters On Real Cars
Load index is not just tire-shop trivia. It affects how a tire handles the weight placed on it every day. A car loaded with people, luggage, pets, tools, or weekend gear puts a steady demand on each tire. If the tire’s rating is too low, heat can build up faster, wear can get ugly, and the vehicle may not react the way it should under braking or during a sharp lane change.
This matters even more on crossovers, trucks, vans, and EVs. Those vehicles can be heavier than they look, and some carry a lot of weight before the cabin even fills up. An electric vehicle can also put more instant torque through the tires, which is one more reason matching the right tire spec matters.
Check The Placard Before You Buy
Your safest starting point is the sticker on the driver-side door jamb. It lists the factory tire size and the cold inflation pressure the vehicle was built around. NHTSA’s tire safety information points drivers to the vehicle placard and sidewall markings when checking tire fit and load-related details.
If the placard calls for a tire with a 94 load index, dropping to a 91 just because the tire is cheaper is a bad move. Matching the factory number or going higher is the normal rule when replacing tires on a stock vehicle.
| Load Index | Max Load Per Tire | Max Load Per Tire |
|---|---|---|
| 84 | 1,102 lb | 500 kg |
| 88 | 1,235 lb | 560 kg |
| 91 | 1,356 lb | 615 kg |
| 94 | 1,477 lb | 670 kg |
| 97 | 1,609 lb | 730 kg |
| 100 | 1,764 lb | 800 kg |
| 104 | 1,984 lb | 900 kg |
| 107 | 2,149 lb | 975 kg |
| 110 | 2,337 lb | 1,060 kg |
How To Read Tire Load Index When Shopping
When you shop for tires, match four things together: size, load index, speed rating, and any special construction marks the vehicle needs. A tire can look close on a retailer page and still be the wrong fit if one of those pieces is off.
Michelin’s load and speed rating explainer spells out a simple rule: the replacement tire should meet or exceed the load and speed capability specified for the vehicle. That lines up with what most tire pros tell customers at the counter.
Standard Load, XL, And LT Tires
You may also run into SL, XL, or LT on the sidewall or product page. SL means standard load. XL means extra load. LT marks a light-truck tire with its own load system. These marks can change how the tire carries weight, but you still match the tire to what the vehicle calls for.
An XL tire can carry more weight than a same-size standard-load tire when inflated as required, which is why some heavier sedans, SUVs, and EVs use them from the factory. But “more” is not a blank check. Ride feel, pressure targets, and wheel fit still need to line up.
Can You Use A Higher Number?
Yes, in many cases a higher load index is fine if the size, wheel fit, and pressure needs still work for the vehicle. Many drivers do this when a tire line is offered in a slightly higher load index than the original spec. Going lower is where trouble starts.
That said, a higher number does not always mean a better tire for the job. A heavier-duty tire can ride firmer and may need different inflation habits. The right choice is the one that fits the vehicle and the way it is used, not the largest number on the shelf.
| Situation | What To Do | Why It Matters |
|---|---|---|
| Same size, same load index | Good match | Closest to factory setup |
| Same size, higher load index | Often acceptable | Adds carrying margin if fit stays right |
| Same size, lower load index | Skip it | May leave the vehicle under-rated |
| XL replacing SL | Check placard and product details | Pressure and ride may change |
| Passenger tire replacing LT tire | Do not swap blindly | Load systems are not the same |
| Towing or full cargo loads | Stay strict with factory spec | Extra weight leaves less room for error |
Common Mix-Ups That Cause Bad Tire Choices
A lot of tire-shopping mistakes come from mixing one rating with another. These are the ones that trip people up most:
- Load index vs. speed rating: one is weight, the other is top speed capability.
- Max sidewall pressure vs. door-jamb pressure: the sidewall shows the tire’s own limit, not the daily pressure target for your car.
- Tire size vs. tire capacity: two tires can share the same size and still have different load indexes.
- Single-tire rating vs. vehicle payload: the tire rating is only one piece of the full weight picture.
One more snag: mixing tires with different load indexes on the same vehicle. Even if the car seems to drive fine at first, it is a mismatch you should fix. The vehicle was tuned around a matched set.
A Simple Way To Pick The Right Replacement Tire
- Read the tire size and load index on the current tire.
- Check the driver-side placard for the factory spec.
- Match the size exactly unless you are changing wheel and tire setup on purpose.
- Choose the same load index or higher, not lower.
- Match the speed rating level the vehicle calls for.
- Ask the installer to confirm the final spec before mounting.
If you carry heavy cargo, tow often, or drive a loaded SUV or van, be extra picky here. That is where a small spec mismatch can turn into heat, wear, and handling trouble far sooner than you’d expect.
The Sidewall Number That Keeps You Honest
Tire load index is a plain number with a big job. It tells you how much weight each tire is built to carry, and it keeps replacement shopping tied to the math your vehicle needs. Once you know where it sits on the sidewall, you can read it in seconds.
Stick with the factory load index or step up, never down, unless a tire pro working from the vehicle specs tells you otherwise. That one habit keeps your tire choice grounded in the car’s real weight needs, not just a matching size on a screen.
References & Sources
- National Highway Traffic Safety Administration (NHTSA).“Tire Safety Ratings and Awareness.”Explains tire sidewall markings, tire safety basics, and the value of checking the vehicle placard when buying tires.
- Michelin USA.“Tire Load Rating & Speed Rating Explained.”Defines tire load and speed ratings and states that replacement tires should meet or exceed the vehicle’s specified load and speed capability.