31X18R15 tires have a diameter of 31.0", a section width of 18.0", and a wheel diameter of 15". The circumference is 97.3" and they have 651 revolutions per mile.
Specs may vary by manufacturer. learn more
When searching for the perfect tire for your vehicle you need options. Click the "Alternate Sizes" button to see a list of similar tire sizes. You can then change the wheel size to see alternate sizes on a different diameter wheel.