Section Width675 mm (26.6")
Aspect Ratio18%
Rim Diameter31"
Overall Diameter1030 mm (40.6")
Sidewall Height122 mm
Circumference3237 mm
675/18R31 — Buy Tires

Everything to know about the 675/18R31 tire size

Size geometry

A 675/18R31 tire has a 675mm section width and a 18% aspect ratio, mounted on a 31-inch rim. Sidewall height works out to 121.5mm (4.78") and overall outside diameter is 1030.4mm (40.57"). At highway speed the tire completes about 309 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 675/18R31 is unavailable, the closest same-diameter substitutes on the same rim are 665/18R31 and 685/18R31. Both keep your speedometer reading within 1% — safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.

Plus / minus sizing options

For a 675/18R31 you can upsize to 685/16R32 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 665/20R30 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.

Vehicle compatibility

0 vehicles in our database run the 675/18R31 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance — match these specs to your wheel before purchasing tires.

Vehicles Using 675/18R31

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