Very often, most people that has cars doesn't know or only have little idea about tires. Most only matters personally is their car itself. Even in the long run, little that we know about tires for as long as we keep on using our car until we notice that we need to change tires already. The first question that will come into our mind is "What is the tire size of your car?" (Usually, we rely on the actual tire of our car to know what is the size of it. And most of the time, we choose tires according to what was already on our car.) Next question will be "What basically are those numbers and symbols embed in the tire means?" And maybe the last one will be "What brand should i buy? On this blog, we will only give further importance on the first two questions than the latter in order for us to understand what are those numbers and symbol means. You may even give advices or share to families and friends when you learn this basic information on tires. Here's the brief rundown of what makes up the tire:
Tire Type
Letter on the sidewall show the types of tires. The common types are represented by these three letters:
• P—For a passenger vehicle tire
• LT—For a light truck tire
• C—For a commercial large vehicle tire
Tire Width
The tire width is measured in millimeters. For example, 215 means 215 millimeters wide
Aspect Ratio
The next number to the tread width is the height of the tire which is the aspect ratio. Aspect ratio is the relationship between a tire’s section height and its section width. A 215/65 means the sidewall height is 65% of 215 mm. The smaller the aspect ration, the shorter the sidewall.
Tire Construction
Right next to the aspect ratio number is a letter that describes the tire construction.
• R - Radial (commonly used)
• D - Diagonal bias
• B - Bias belted
Rim Diameter
The next number in line is the rim diameter. This is measured in inches. As example, R15 means 15 inches is the rim diameter.
• Note: Please make sure to read your vehicle owner’s manual or the sticker on the driver’s door wall to find out the proper tire wheel diameter for your vehicle.
Speed Rating
The speed rating is the tire’s maximum speed capability under ideal conditions, and it is represented by a letter symbol. For example, the number and letter symbol 95H letter H represents a maximum speed rating of 210 km/h. Speed ratings can be found in tire catalogs. Here are some other examples of speed rating:
• L - 120kph
• N - 140kph
• P - 150kph
• H - 210kph
Tread Wear Index
The tread wear index is the tire’s resistance to tread wear. The higher the number, the more resistant the tire is to tread wear. Today’s common tires have a tread wear index of 300 and above.
Traction
Traction index is a measure of the tire’s ability to stop on wet pavement or concrete. It is represented by the letter AA, A, B, or C. The highest grade of traction is AA and the lowest is C.
Temperature Resistance
Temperature rating indicates the tire’s ability to dissipate heat. It is represented by the letters A, B or C. The highest rating is A and the lowest is C. A would be found in high-performance road tires.
Load Index/Maximum Load
The load index is a code number corresponding to the maximum load-carrying capacity of the tire at the designated speed rating. The maximum load is the maximum weight on a tire, including the weight of the car, its occupants, and cargo. It is measured in kilograms or pounds. The load index codes and the corresponding maximum loads can be found in tire catalogs.
For example, the first number on speed rating 95H, 95 corresponds to a maximum load capacity of 1,510 lbs per tire. It can be found also on the sidewall of the tire as well bearing MAX LOAD.
