There's a lot of numbers associated with picking out tires for your car, but one you may not look too closely at is arguably ...

We’re going to use the code P205/65R16 75H as an example. Tire type. The first letter of the code describes what type of vehicle the tire is meant for. P indicates a passenger vehicle.

In particular, we are concerned about the "V," because that position in the code defines the speed capability of the tire. Back in the '60s, there were only three speed codes.

Confused about the pressure number on your tire? Learn why the tire's pressure rating isn't what you should use and what to ...

It might help if I explained "speed ratings." The rating does not tell you how fast the tire can go, rather how long it can be expected to last at a sustained speed.

While we found prices are similar to S- and T-rated tires, H-rated tires didn't last as long in our treadwear test--an average of 49,180 miles, versus 61,080 for our S- and T-rated tires.