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 IndexPoundsKilogramsLoad IndexPoundsKilograms
71761345911356615
72783355921389630
73805365931433650
74827375941477670
75853387951521690
76882400961565710
77908412971609730
78937425981653750
79963437991709775
809924501001764800
8110194621011819825
8210474751021874850
8310744871031929875
8411025001041984900
8511355151052039925
8611685301062094950
8712015451072149975
88123556010822051000
89127958010922711030
90132360011023371060

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 SymbolMaximum speed (km/h)
N140
P150
Q160
R170
S180
T190
U200
H210
V240
Z240
W270
Y300

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.

qu35324_800

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

 

Subscribe
Notify of
0 Comments
Inline Feedbacks
View all comments