Section Width165 mm (6.5")
Aspect Ratio108%
Rim Diameter21"
Overall Diameter890 mm (35.0")
Sidewall Height178 mm
Circumference2795 mm
165/108R21 — Buy Tires

Everything to know about the 165/108R21 tire size

Size geometry

A 165/108R21 tire has a 165mm section width and a 108% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 178.2mm (7.02") and overall outside diameter is 889.8mm (35.03"). At highway speed the tire completes about 358 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 165/108R21 is unavailable, the closest same-diameter substitutes on the same rim are 155/115R21 and 175/102R21. 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 165/108R21 you can upsize to 175/95R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 155/123R20 (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 165/108R21 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 165/108R21

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