What do Tire Numbers mean
Besides the brand name and model, atire sidewallserves as a kind of board providing information about its intended use, ratings and characteristics. But, what do the numbers on a tire mean? These alphanumeric codes integrate information that goes from size to maximum inflation pressure to load capacity. Thus, these markings can help a car owner make a decision as to the right tire to buy for a particular vehicle and select the most suitable ones for a specific use and climate.Main markingsOne of the most distinct markings printed on a tire sidewall provides information about thetire sizeand may read something like this: P 135/80 R 14, as the one shown on the picture above. Although the particular intended use of a tire may be stated right out, an initial letter may be given to denote whether it is designed for a passenger (P) car, temporary (T) use, or for commercial (C) vehicles. This initial letter is followed by the width of the tire in millimeters (135) and the height of the tire (65)-or aspect ratio-denoted as a percentage of its width.After this code, the next letter denotes the tire design. For example, this could be a radial (R), bias (B), or diagonal bias (D) tire. Finally, next to the tire construction type comes the inner dimension or rim diameter in inches (14). Under this particular code, a smaller one can provide a Department of Transportation(DOT) number, if the tire was made in the United States. This means the tire has passed DOT safety tests and provides manufacturer identification, plant location and construction date.Other important informationIn addition to the particular dimensions, a tire's sidewall contains other important information like maximum load capacity-the amount of weight the tire can carry-stated as MAX. LOAD 400 Kg (880 lbs.), for example. Usually, this other information is given in much smaller type. This includes maximum pressure or inflation pressure, given in kilopascal units (303 kPa) and pounds per square inch (44 PSI); number of plies used in its construction-for example, 2 polyester cord; traction capacity rating-A (best), B (medium), or C (basic); and whether a tire is suitable for mud and snow (M + S) conditions.All this data can be used to fit a particular vehicle with the best suitable set of tires. Although car manufacturers make their recommendation for the best tires for a particular vehicle, a car owner-knowing what do the numbers on a tire mean-may use this information to fit a vehicle with a different set of tires to suit a particular climate or driving conditions.
