Beginner’s Guide: How To Read A Tire Sidewall

Tires carry a lot of information on their sidewalls; unfortunately, it’s all in code. In addition to the tire’s brand and tire model, there is a lot of information provided by the manufacturer on the sidewalls of the tires they produce. This information includes the tire’s basic dimensions and identifies when it was produced, the types of materials used internally to reinforce the rubber, along with the tire’s maximum inflation pressures and loads etc.

sidewall-tire-illustration

Consider an example if we have a tire which reads P215/65 R15 89H on its sidewall, the reading would mean:

VEHICLE CLASS – P215/65R15 89H

The first alphabet represents the class of the vehicle, though not all tires include this letter.
P: Passenger Car
LT: Light Truck
SP: Special Trailer
T: Temporary (restricted usage for ‘Space-Saver’ spare wheels)

3 DIGIT NUMBER – P215/65R15 89H

The ‘nominal section width’ of the tire in millimeters; the widest point from both outer edges of a tire.

2 OR 3 DIGIT NUMBER – P215/65R15 89H

The ‘aspect ratio’ of the sidewall height to the total width of the tire, as a percentage. If no information is provided, it is assumed to be 82%. If the number is larger than 200, then this is the diameter of the entire tire in millimeters.

AN OPTIONAL LETTER – P215/65R15 89H

Indicating construction of the fabric carcass of the tire.
B: Bias belt
D: Diagonal
R: Radial

2 DIGIT NUMBER – P215/65R15 89H

The wheel diameter, in inches, that the tire will fit.

2 OR 3 DIGIT NUMBER – P215/65R15 89H

The load index is the tire size’s assigned numerical value used to compare relative load carrying capabilities. In the case of our example the number 89 identifies the tires ability to carry approximately 580 kg of weight. The higher the tire’s load index number, the greater its load 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

1 OR 2 DIGIT/LETTER COMBO – P215/65R15 89H

Represents the speed rating. The speed rating code is made up of either one or two letters, or one letter and one number. It indicates the maximum permitted speed that the tire can sustain for 10 minute endurance without being in danger. Considering the above example, the H rating means the tires can sustain a 10 minute endurance at a maximum speed of 210 km/h. Tires with a speed rating higher than 300 km/h include a ‘Y’ in parenthesis. The load rating is often included within the parenthesis, e.g. (86Y).

Speed Symbol Maximum speed (km/h)
N 140
P 150
Q 160
R 170
S 180
T 190
U 200
H 210
V 240
Z 240
W 270
Y 300

RIM WIDTHS

The allowable range of rim widths for a specific tire size, running a tire on a rim size or type not approved by its manufacturer can result in tire failure and a loss of vehicle control.

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MANUFACTURING INFO

It specifies the company, factory, mold, batch, and date of production (2 digits for week of the year plus 2 digits for year). For example, if the last four digits of the code are 2511, that means that the tire was manufactured during the 25th week of the year 2011.

ADDITIONAL MARKS

There can be numerous other markings on a typical tire, these may include:

  • M+S, or M&S: Mud and Snow; all-weather tires, with above-average traction in muddy or very light snowy conditions, and for low ambient temperatures. Not classified as a winter tire unless it has the snowflake and mountain symbol. Studded tires have an additional letter, ‘E’ (M+SE).
  • BSW: Black Sidewall
  • WSW: White Sidewall
  • OWL: Outline White Lettering
  • VSB: Vertical Serrated Band
  • TL: Tubeless
  • TT: Tube-type, tire must be used with an inner-tube
  • C: Commercial; tires for light
  • LL: Light Load; tires for light usage and loads
  • SL: Standard Load; tire for normal usage and loads
  • XL: Extra Load; tire for vehicles of heavier standard weights
  • RF: Reinforced tires

 

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UsmanAnsari
A car enthusiast associated with the 3D Animation industry of Pakistan since year 2000 having worked with leading organizations and production facilities across Pakistan. Passionate about cars ever since, and a strong desire to see the automobile industry of Pakistan flourish in true means, Usman Ansari has a vast experience of writing for major automobile portals of the country. Drives a Honda City SX8 as a daily runner, as well as a 10th generation Toyota Corolla Gli. CarSpiritPK.com was initiated by Usman Ansari in May 2016.
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