For tires using the P-metric designation (e.g., P245/50ZR16)
Format:
Code:
P | Passenger |
LT | Light truck |
T | Temporary |
LTP | Light truck, personal use |
Width:
Width at widest point, sidewall to sidewall, in millimeters.
Aspect Ratio:
Tire height in mm, measured tread to bead, divided by width above, multiplied by one hundred.
Speed ratings:
The maximum speed the tire can maintain at its maximum load rating
Q | 100 mph |
R | 106 mph |
S | 112 mph |
T | 118 mph |
U | 124 mph |
H | 130 mph |
V | 149 mph |
W | 168 mph |
Z | more than 168 mph |
Construction:
R | Radial ply |
B | Bias belted |
D | Diagonal bias |
Size:
The diameter of the wheel the tire is designed to be mounted on, in inches.
Other information:
Maximum Air Pressure | This is the max pressure the tire is designed to hold (note this is more than the recommended inflation pressure) |
Maximum Load | Weight the tire can support |
Load Index | A code that indicates the maximum weight the tire can carry at its speed indicated by its speed rating |
Construction | Tells the number and type of plies used in the construction of the tread and sidewall |
DOT Serial Number | Identifies the plant, manufacturer, and date of production |
Tread Wear Index | A rating of the tire's resistance to wear. 100 is the reference. A 250 rating indicates 2.5 times the wear resistance of the reference tire. This number cannot be accurately translated to mileage. |
Traction Index | A rating of the tire's ability to stop on wet pavement. There are three grades, A, B, and C, with A being the best. This index does not reflect the tire's traction performance on dry, snowy, or icy pavement. |
Temperature Index | A rating of the tire's ability to dissipate and resist heat. There are three grades, A, B, and C, with A being the best. |