The series of numbers and letters on a tire’s sidewall might look like a random string of characters, but they actually hold essential information about the tire’s specifications. These markings help determine the proper fit, performance capabilities, and safety standards for your vehicle in Belleville, IL. Understanding what they mean can be helpful when it’s time to replace your tires or check their condition.
Tire Type and Width
One of the first indicators on a tire is the type designation. This shows whether the tire is intended for passenger vehicles, light trucks, or other specific uses. Immediately following this is a number that represents the width of the tire. This measurement is taken from sidewall to sidewall and is expressed in millimeters. The width affects handling and performance, with wider tires often offering more grip, while narrower ones may be more efficient for fuel economy.
Aspect Ratio and Construction
Next in the sequence is a number that refers to the aspect ratio, which is the height of the sidewall compared to the tire’s width. This figure is given as a percentage and has a direct impact on the feel of the ride. A lower aspect ratio typically results in a firmer, sportier ride, while a higher ratio offers more cushion and comfort. The letter that follows indicates the tire’s construction. The most common construction method used today is radial, where the internal layers of the tire run perpendicular to the direction of travel. This design provides better control, longer tread life, and improved fuel efficiency compared to older methods.
Wheel Diameter, Load Index, and Speed Rating
After the construction type, the next number shows the diameter of the wheel that the tire is designed to fit. This measurement is expressed in inches and helps ensure the tire matches the size of your vehicle’s wheels. Following the wheel diameter, there is usually a two- or three-digit number that represents the load index. This code identifies the maximum weight the tire can support when properly inflated. Each number corresponds to a specific load capacity, which is essential for safety and vehicle performance. The final letter in the sequence refers to the speed rating. This indicates the maximum speed at which the tire can safely carry a load. The rating is assigned based on laboratory tests and helps drivers select tires that match their typical driving conditions.
Additional Information
Other markings on the tire may include manufacturing details such as the date and location of production. There are also designations for special capabilities, such as suitability for mud and snow or approval for winter driving conditions. You may also see quality grading for treadwear, traction, and temperature resistance.
Why This Matters
Knowing what the numbers on your tires mean isn’t just useful when shopping for replacements in Belleville, IL, it’s a key part of vehicle safety. Properly matched tires contribute to better fuel economy, smoother handling, and longer-lasting tread. By understanding these markings, drivers can make informed decisions and maintain their vehicle’s performance with confidence.
If you live in Belleville, IL and are looking for new tires, call Rowan Tire & Auto Repair today.
