Section Width125 mm (4.9")
Aspect Ratio166%
Rim Diameter20"
Overall Diameter923 mm (36.3")
Sidewall Height208 mm
Circumference2900 mm
125/166R20 — Buy Tires

Everything to know about the 125/166R20 tire size

Size geometry

A 125/166R20 tire has a 125mm section width and a 166% aspect ratio, mounted on a 20-inch rim. Sidewall height works out to 207.5mm (8.17") and overall outside diameter is 923.0mm (36.34"). At highway speed the tire completes about 345 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/166R20 is unavailable, the closest same-diameter substitutes on the same rim are 115/180R20 and 135/154R20. 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 125/166R20 you can upsize to 135/144R21 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/191R19 (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 125/166R20 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 125/166R20

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