How to Read Tire Size
If you’re wondering how to read tire size, this guide is for you. At Faulkner Mazda, we know that choosing the right set of tires can make all the difference when it comes to performance and safety, so we created this guide for drivers in the Harrisburg, Mechanicsburg, and Carlisle areas.
1. Find your Tire Size
The first step is knowing the right tire size for your vehicle before you are able to know how to read tire size. You can find this in several places, such as:
- Your owner’s manual
- The sidewall of your current tires
- The driver-side door jamb
- The manufacturer’s website
You’re also welcome to call your local dealership at any time to speak with a factory-trained professional who can offer advice.
2. Understand Your Tire Size
When you locate your tire size, it’ll appear as a long string of letters and numbers. For our example, we looked at the Sport trim of the 2018 Mazda3 sedan. This car requires the following size as recommend by the manufacturer’s website:
- P205/60R16 91H
This gives us tons of information; Every letter and number means something different and paints a clear picture of your appropriate tire size.
Vehicle Type: The first part of our example is the letter “P.” This indicates the type of vehicle the tire is meant for. In our case, it’s a passenger vehicle. It may also read “LT” for light truck, “T” for temporary, or “ST” for special trailer.
Width: Next in the sequence are three numbers. These refer to the tire’s width as measured from sidewall-to-sidewall. In our example, the proper tires for the Mazda3 should measure 205 millimeters.
Aspect Ratio: The next number is the height-to-width aspect ratio. Higher ratios tend to create more of a donut shape. Our example aspect ratio of 60 tells us that the sidewall height is 60% of the tire’s overall width.
Internal Construction: After the aspect ratio is the letter “R.” This indicates that the tires should have radial internal construction. This is when the internal body piles radiate outward from the center. “R” is most common, but you may also see the letter “D.” This stands for diagonal construction, which is when the internal body piles crisscross each other diagonally.
Rim Diameter: The final number refers to the rim diameter. The 2018 Mazda3 sedan has rims with a diameter of 16 inches.
3. Choose the Right Performance Indicators
You may have noticed that we left out the last letter and number, which is 91H in our example. This isn’t related to tire size, but it’s important because it tells you their load carrying capacity and speed rating. You want these to match the car’s capabilities to maximize performance without overworking your tires.
In our example, the indicator of 91 indicates that they can carry a load of 1,356 pounds. The letter H tells us that they can handle a maximum speed of 130 MPH.
You can determine performance indicators by cross-referencing the tire manufacturer’s index.
We’ll Help You Read Your Tire Size
If you have any questions about how to read tire size, let the experienced professionals at our Harrisburg area dealership help. We’ll gladly pick out the right set for your drives around Mechanicsburg and Carlisle and will even install them for you.