On the side of a tire under the brand name, you'll find every piece of information you need to know about the tire. The size, make, model, load index and speed rating can be found in a series of numbers on the sidewall of your tires.
P
215
60
R
15
The P means that the tire is designed for a Passenger car. LT means Light Trucks. If you choose to use a P rated tire on a vehicle that originally took a LT, the maximum load carrying capacity of the tire should be reduced by 9%.
This is the width in millimeters of the tire from sidewall to sidewall when it's unstressed and you're looking at it head on (or top-down).
This is the height of the tire sidewall, or section height, expressed as a percentage of the width. It is known as the aspect ratio.
This tells you that the tire is a radial construction. Most of today's tires are radials, but occasionally you may see a D or a B on the tire indicating that the tire is a bias ply tire. Never mix radial and bias ply tires on a vehicle.
This is the diameter in inches of the rim of the wheel on which the tire has been designed to fit.
Load Index
This indicates the tire's load index as established by the Rubber Manufacturers Association. The load index can range from 0 to 279 and indicates how much weight the tire is certified to carry at maximum inflation pressure.
Make sure that the tire you replace has the same carrying capacity as the one you are taking off. You can do this by using a tire with the same load index, or by checking the maximum load capacity of the tire which is printed in fairly small print near the wheel. On trucks you often won't see this designation in which case you should look for a Load Range such as C, D, E, or F.
Load Index
Maximum Load (lbs)
90
1323
91
1356
92
1389
93
1433
94
1477
95
1521
96
1565
97
1609
98
1653
99
1709
100
1760
101
1815
102
1870
103
1925
104
1980
105
2035
106
2090
Speed Ratings
All tires are rated with a speed letter. This indicates the maximum speed that the tire can sustain for a ten minute endurance drive without falling to pieces. We do not recommend using a tire with a speed rating lower than that which the vehicle manufacturer recommends for your car, or mixing tires with different speed ratings on any vehicle.
Load Index
Speed Ratings