How to Measure Tire Sizes
Buying a new set of tires is just like buying shoes: you have to make sure that your tires fit perfectly on the wheel. Tires that are too small or too big for your car, or tires not designed for your vehicle, are potential safety hazards that can affect you on the road. To get the right set of tires for your car, here are some reminders about tire sizes.
Components
Tire manufacturers use a special code to denote the dimensions and the specifications of a set of tires. The set of numbers and letters are standardized among tire manufacturers. You’ll get the same specifications for a tire size regardless of what brand it is.
Type
The tire size usually begins with a group of letters that denote the specifications of the tire, and for what particular vehicle it is used for. Here are some of the tire types common on the market today:
P refers to tires designed for most passenger vehicles.
T refers to a tire specifically designed as a space saver or as a spare tire.
LT refers to tires designed to bear light weights of cargo.
C refers to tires designed to carry commercial cargo.
ST refers to tires designed for trucks and heavy equipment.
Section Width
The section width describes the measurement of the cross-section of the tire. The section width is the distance between the widest part of the outer sidewall, and the widest part of the inner sidewall. The number is expressed in millimeters, located after the tire type.
Tire Profile
The tire profile is the height of the sidewall. Also known as the aspect ratio, the tire profile is expressed as the percentage value between the ratio and the section width of the tire. Most passenger tires have the value “50″ expressed on the tire size.
Construction
Construction specifications are sometimes indicated on tire sizes;
R refers to tires made with radial construction. Most cars use radial tires, and you won’t find a problem looking for one at the auto supply store.
D refers to tires made with a diagonal bias. ”D” tires are usually equipped and fitted on trucks and trailers.
B tires are belted tires. The tires are made in such a way that the tires are reinforced with steel cables or belts, although these types of tires are no longer common.
Diameter
The diameter of the tire is expressed in inches. The value is usually a whole number, although sizes with half-inches are often used for trucks, trailers, and heavy equipment.
Tire Size Calculators
Tire size calculators are also common on the Internet, where you can input certain values like tread width, the size of your rims, and the make of your car. Calculators are useful if you do not have enough knowledge of tire sizes, or if you’re looking for a particular specification but you’re missing out on some measurements of the tire.
The right tire can mean all the difference between a safe drive and a dangerous one. With these tips, you can buy a set of tires designed and custom-fit to make your driving experience safe and secure.