Each truck requires the right tire size, as recommended by the manufacturer. Choosing the correct tires can boost performance and fuel efficiency. To do so, pay attention to the numbers and letters on the sidewall tire code – they hold the key to understanding your tires. In case of a flat tire, consider calling a mobile tire service to get you back on the road quickly.

Tire Size Explained 

A normal set of sidewalls will have something that looks like this: LT295/75R22.5. Here’s how to read this set of characters. 

When it comes to tire codes, it’s important to understand the Sidewall Tire Code. This code is especially important for passenger, light truck, and special trailer tires, which have a prefix to indicate their specific type. For example, LT denotes light truck tires, while ST stands for special trailer. It’s also worth noting that some commercial truck tires have a C at the end of their code, indicating their specific use. By decoding the Sidewall Tire Code, you can ensure you’re getting the right tire for your vehicle.

295 – This three-digit number refers to the tire’s width, from sidewall to sidewall, in millimeters. Smaller tires than recommended for your truck may compromise the vehicle’s stability. 

75 – This number refers to the aspect ratio of the tire. It’s calculated by dividing a tire’s height off the rim by the width. This tire’s height is 75% of its width. A lower aspect ratio usually performs better because of the tire’s stability. 

R – The second letter refers to the tire’s construction. R is for a radial tire, which is the industry standard. The tire’s layers run radially across the tire. D is for diagonal piles, or bias construction. 

22.5 – This is the wheel’s diameter, in inches. 

When examining a tire, it’s essential to understand the Sidewall Tire Code. In addition to this code, there may be other numbers and letters on the tire, such as DOT. The DOT letters indicate that the tire meets all federal standards in the US, and the series of letters and numbers that follow provide information about where and when the tire was produced. For retread tires, a new DOT code is added after production. The most critical digits of the DOT code are the last four, which tell you when the tire was manufactured. By decoding the Sidewall Tire Code and understanding these additional markings, you can make informed decisions about your tires.

Replacing Tires with Different Size Tires—Not Recommended! 

On a commercial truck, the tires should be similarly sized. When you replace tires, you need to choose tires with the same rating. Trucks that run with improperly sized tires have reduced traction and stability. Tire size impacts safety and fuel efficiency. Mismatched tires can also lead to uneven tread wear, which shortens the lifespan of your tires. When you call a mobile tire service, you want the same size tires you currently have on your truck. 

STTC Offers 24/7 Mobile Tire Services

When your commercial truck needs tires, reach for the mobile tire service provided by STTC. We come to your truck to safely replace any tires and to get you back on the road as soon as possible. With our tire management program, we can assess old tires for tire retreading to save you money by getting more life out of used tires. 

Call us now at 610-954-8473 or contact us online to learn more about our mobile tire service. 

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Further Reading on Tire Retreading Insights

Further Reading on Commercial Truck Tires 101