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Tire Ratings
You may have noticed the letters and numbers on the side of your tires. But what exactly does it all mean?

The letters and numbers, correspond to the ratings of your tires. Here we teach you what it all means, in plain English.

Let's use an example of a tire like P180/55R15 85T to teach you what it all means. The final 85T is known as the service description of the tire. This is gonna tell you the tires load index and speed rating.Tire manufacturers have been required since 1991 to display this information on the tire.

The service description is important, because it identifies the amount of weight the tire can carry and the maximum recommended speed of the tire.

The first two digits of the service description corresponds to the tires load index. So in the example we take the 87T, 87 represents a load index of the tire. The higher the number of the low index, the higher the carrying capacity of the tire. Below is a chart showing load indexes and their corresponding carrying capacity.

Load Index Pounds Kilograms
Load Index Pounds Kilograms
71 761 345 91 1356 615
72 783 355 92 1389 630
73 805 365 93 1433 650
74 827 375 94 1477 670
75 853 387 95 1521 690
76 882 400 96 1565 710
77 908 412 97 1609 730
78 937 425 98 1653 750
79 963 437 99 1709 775
80 992 450 100 1764 800
81 1019 462 101 1819 825
82 1047 475 102 1874 850
83 1074 487 103 1929 875
84 1102 500 104 1984 900
85 1135 515 105 2039 925
86 1168 530 106 2094 950
87 1201 545 107 2149 975
88 1235 560 108 2205 1000
89 1279 580 109 2271 1030
90 1323 600 110 2337 1060

The next important number is the speed rating, the letter after the load index number, gives us the tires speed rating. Using our example of P180/55R15 85T, the letter T will give us the tire speed rating. In this case it's 118 mph or 180 kmh, this means that the tire should never be driven faster than 118 mph. Of course, most highways won't permit this type of speed anyways.

Below is another chart showing you the letter and corresponding speed rating for each tire. Z rated tires were originally designed to be the highest speed rated tires. Z means in excess of 149mph. However the V, W and Y ratings were later introduced, which further clarify the capability of these extreme speed tires.
Speed Rating Maximum Speed Type Of Tires
L 75mph / 120kmh Light truck & off-road
M 81mph / 130kmh Spare Tires
N 87mph / 140kmh  
P 93mph / 150kmh  
Q 99mph / 160kmh WinterTires
R 106mph / 170kmh Light truck Tires
S 112mph / 180kmh Family sedans & vans
T 118mph / 190kmh Family sedans & vans
U 124mph / 200kmh  
H 130mph / 210kmh Sport sedans & coupes
V 149mph / 240kmh Sport sedans, coupes & sports cars
W 168mph / 270kmh High end sports cars / exotics
Y 186mph / 300kmh High end sports cars / exotics
Z in excess of 149mph High end sports cars / exotics