Section Width185 mm (7.3")
Aspect Ratio139%
Rim Diameter12"
Overall Diameter819 mm (32.3")
Sidewall Height257 mm
Circumference2573 mm
185/139R12 — Buy Tires

Everything to know about the 185/139R12 tire size

Size geometry

A 185/139R12 tire has a 185mm section width and a 139% aspect ratio, mounted on a 12-inch rim. Sidewall height works out to 257.1mm (10.12") and overall outside diameter is 819.1mm (32.25"). At highway speed the tire completes about 389 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 185/139R12 is unavailable, the closest same-diameter substitutes on the same rim are 175/147R12 and 195/132R12. 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 185/139R12 you can upsize to 195/125R13 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 175/154R11 (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 185/139R12 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 185/139R12

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