General Information Of the Tire Code & Tips of Buying New Tire

Did you know what is the meaning of the "Code" printed on the side wall of the tire. Sometimes we do not know what kind of tires suitable for our use. Usually we just tell the size of the tire to tire shopkeepers, and some just say "change tire" verbally and let the shopkeepers make decisions what tire to use. Inappropriate use of tires with the weight of the vehicle and the speed can lead to tire failure to function properly and may cause accidents. So, here i would like to share with you what is the meaning of the "Tire Code". Just take a few minute to read this article and it would save your money and the most important is your safety.

The "Code" or it standard name "The ISO Metric tire code" is a national tire standards influenced by the The European Tyre and Rim Technical Organisation (ETRTO) and the Tire and Rim Association (TRA) .

Let's see one of the example that appear at the side wall of the tire

165/55/R14  72H

Here is the explanation for this code

165 - The "nominal section width" of the tire in millimeters; the widest point from both outer edges.

*some of the tire got letter infront of the first three digit number.. eg: P165 or T165 etc. indicating the intended use or vehicle class for the tire;

          P: Passenger Car
        LT: Light Truck
        ST: Special Trailer
          T: Temporary (restricted usage for "Space-Saver" spare wheels)

55 - The "aspect ratio" of the sidewall height to the total width of the tire, as a percentage (mean 55%)

* to get the height of the sidewall in milimeters;

                  
                        nominal width x (aspect ratio/100)= height of the side wall in milimeters

 example in this case 165/55/R14            165 x 0.55=90.75mm

An optional letter indicating construction of the fabric carcass of the tire:

R - Radial

D - Diagonal

B - bias belt (where the sidewalls are the same material as the tread, leading to a rigid ride)

*mean that, the 165/55/R14 is the Radial fabric carcass (use mostly on the passanger vehicle)

14 - Diameter in inches of the wheel that the tires are designed to fit to the rim

72- Load index (refer to the Standard Load tabel below)

*mean that max load for this tire is 355 kg (780 lb)

H - Speed rating (refer to the speed rating table below)

*mean that max speed for this tire is 210km/h or 130mph

Other Additional Important Information

Treadwear: eg: 240 *the highest number the slowest the thread to be thin/wear

Traction: AA (Highest in Quality), followed by A, B and C

Temperature:  A (whereas the weather are hot)

                     B (Normal Weather)

                     C (Cold Weather)

Manufacturing Week and Year: Example 1411

First two digit number 14: The week of fourteen of the year

Last two digit number 11: Year of 2011

*mean that the tire mark as 1411 was produced on the first week of April 2011