Tire load index and speed rating chart

The full load index table from 82 to 126 and the speed rating letters, plus the one rule: never go below the door-jamb number.

A tire that bolts up fine can still be the wrong tire. Size gets it on the car. Load index and speed rating decide whether it belongs there. Get either one wrong and the tire is legal to sell and wrong to install, and nothing about the tire itself will warn you: it mounts, it balances, it looks correct on the rim.

What load index and speed rating actually mean

Load index is a code, not a weight. "98" doesn't mean 98 pounds. Look it up instead. It means look the number up in a table, and that gives you the pounds one tire can carry at its maximum pressure. Speed rating works the same way: a letter, H or V or T, that maps to a top speed the tire is built to sustain. Two numbers. Both matter.

Both numbers sit right after the size on the sidewall. P225/65R17 98H reads as a 225 mm wide, 65-series radial on a 17-inch rim, load index 98, speed rating H.

One example, start to finish

A sedan's door sticker reads P225/65R17 98H. A customer brings in a tire off a similar-looking car marked 225/65R17 91V. Same size, different letters and numbers, and that's the whole problem in one example. Index 91 caps out around 1,356 pounds per tire, well under the 1,653 pounds the door sticker calls for. V actually tops out higher than H too, at 149 mph against 130, so speed isn't the issue in this example. Load is. That tire doesn't go on this car, no matter how good the tread looks, because the number that matters lives on the door, not on whatever tire someone happened to bring in.

The full load index table

Every number is pounds per tire, at that tire's maximum pressure. Multiply by four for a rough sense of total capacity, but remember the axle rating on the door jamb is what actually governs, not your own arithmetic.

Why "close enough" doesn't work here

A load index one or two points low might look fine on the rack and still leave a work truck under-rated for what it hauls. Don't round down. Never go below the door-jamb rating. That sticker, usually inside the driver's door, lists the load index and speed rating the manufacturer built the car around, and it's the number to match. Not the number that happened to come off the car it's replacing, and not the number on a tire that's simply in stock and close enough.

Load range shows up on light truck tires too

LT-prefixed tires often carry a load range letter right next to the size: C, D or E. It's a separate marking from load index, tied to how much air pressure the tire's built to run and how much weight the carcass can take at that pressure. A work truck spec'd for load range E won't perform the same on a set of load range C tires, even when the load index number on the sidewall looks close enough on paper. When you're reading a size off a truck, check both numbers: the load index in the table above, and the load range letter sitting next to it. Check the letter too. Log both when you enter a used LT tire, because a customer hauling a trailer is going to ask about the letter before they ask about anything else.

The speed rating table

Y-rated tires top out at 186 mph. A rating shown as (Y), in parentheses, means over 186 mph and shows up mostly on exotic performance tires. Z is an older code that just means over 149 mph, and it still gets stamped inside the size on some performance tires even when the sidewall also carries a separate W or Y letter.

Reading it backward, for a customer

Most customers don't want the table. They want one sentence: this tire carries as much weight and handles as much speed as the one that came on your car, or more, never less. Match it, don't guess. Say that, point at the door sticker if they want proof, and move on. Nobody at the counter needs to hear the word "index."

Where this shows up on a used tire

A used tire's load index and speed rating don't change with wear. Only its condition does. When you price a used tire or fill out the receipt, the load index and speed letter belong right next to the size on both. A mismatched set, four tires with three different load indexes, is the kind of thing that's invisible until a customer's back with a complaint about a truck that feels wrong under load.

It costs nothing to write two extra characters on a tag. It costs an afternoon, and a customer's trust, to explain after the fact why a tire that fit the rim didn't fit the job.