Your Tires Are Trying to Tell You Something
Usually a tire purchase happens in a hurry – you’ve had a flat, or want to mount a new set of tires during some downtime. Sure, the tire dealer helps you figure out the best tires for your vehicle. But have you ever looked at the numbers encoded on the sidewall of the tire?
Those cryptic numbers hold a font of information that can help you select the right tire and get the most out of its life span. The sidewall numbers tell you everything you need to know about the tire, including its dimensions, construction, operating characteristics, and manufacturer.
The easiest way to understand it all is to look at a sample sidewall code and break it down.
“It’s important that customers understand the numbers on the sidewall because they indicate when the tire was manufactured, the size, the ratings and the conditions best suited for the tire,” says Sue Leonard of Bauer Built Tires.
On a common passenger vehicle tire, the sidewall code might read P225/45R17 91V. Starting at the left side, P stands for passenger tire. You might also see LT for Light Truck, ST for special trailer or T for temporary. No letter indicates a Euro-Metric tire. Commercial tires may carry a C designation in the front of the service description, e.g. C109R.
Next, the 225 indicates the tire width in millimeters, from sidewall to sidewall. Larger numbers mean a wider tire.
The next number, 45, reflects the aspect ratio, which is the sidewall height as a percentage of the section width. So the sidewall height of this tire is 45% of 225, or approximately 3.98 inches.
The letter R stands for radial construction, which is the most common for passenger cars and light trucks. Other letters such as B or X may indicate bias ply construction.
The number 17 is the diameter of the beads or the size of rim the tire is designed to fit.
The last number, 91V, is the service description which contains the load index and the speed symbol. The load index relates to a DOT table that lists the maximum load that can be carried at the speed indicated by the speed symbol. The speed symbol, V in this instance, corresponds with a maximum speed in the DOT Speed Rating chart.
There are other sets of numbers you’ll see on the sidewall, the DOT Code and the Tire Identification Number, or TIN. The DOT symbol signifies the tire has passed Department of Transportation requirements. The 10-12 numbers of the TIN indicate the manufacturer, tire size, the tire type, and the final set of four numbers indicate the week and year of manufacture.
Next time you’re in the market for tires, look to Bauer Built, one of the largest commercial and passenger/light truck tire dealers and retread tire manufacturers in the U.S. Consult with a tire manufacturer or your trusted tire specialist at Bauer Built to find the tire that’s best suited for your situation.
For more insights and tips on tire maintenance and related services, visit us online.
Categories: Bauer Built Blog, Tire Care Tips
