How We Measure Tires

Here at Tire Rack, we measure, test, and recommend tires to our customers every day. The great quality of Tire Rack is that we have surveys on all of our tires. On our test track, we drive to compare "like" to "like" tires within the same survey category.

For example, we only compare Ultra-Performance High Season vs. Ultra-High Performance All-Season, not Ultra-High Performance Summer vs. Ultra-High Performance All-Season. As we hopefully approach warmer weather, I invite you to get out, unravel your vehicle from the depths of its garage--and drive. Perform some research, take a look at our tire surveys, and have fun!


Wednesday, October 17, 2012 by David

What do the numbers measure ? example : 235/70 17
Is the 235 the width or rim lip to top of tire (sidewall)
Is it measured in millimeters ?
Thursday, October 18, 2012 by Grant

Thank you for your questions.
Example: 235/70R17:
"235" = The "235" indicates this tire is 235 millimeters across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel. This measurement is also referred to as the tire's section width. Because many people think of measurements in inches, the 235mm can be converted to inches by dividing the section width in millimeters by 25.4 (the number of millimeters per inch).

I hope this helps. Please let me know if I can help further.

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