TireSizesFinder

235/55R20 vs 285/35R22

285/35R22 is 0.32 in (8.2 mm) shorter than 235/55R20, a −1.07% diameter difference. With the speedometer set for 235/55R20, an indicated 60 mph is 59.4 mph on 285/35R22.

Is this a safe swap?

Diameter difference −1.07%: within the ±3% guideline

By overall diameter alone, 285/35R22 falls inside the ±3% range commonly used as a guideline when replacing 235/55R20. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 235/55R20 (30.18 in) vs 285/35R22 (29.85 in)235/55R2030.18 in × 9.25 in285/35R2229.85 in × 11.22 in
Side profile and tread width, drawn to the same scale.
235/55R20 vs 285/35R22 differences
Measurement235/55R20285/35R22Difference% diff
Overall diameter30.18 in (766.5 mm)29.85 in (758.3 mm)−0.32 in (−8.2 mm)−1.07%
Sidewall height5.09 in (129.3 mm)3.93 in (99.8 mm)−1.16 in (−29.5 mm)−22.82%
Section width9.25 in (235.0 mm)11.22 in (285.0 mm)+1.97 in (+50.0 mm)+21.28%
Circumference94.80 in (2,408.0 mm)93.79 in (2,382.3 mm)−1.01 in (−25.8 mm)−1.07%
Revolutions per mile668676+7+1.08%
True speed with the speedometer calibrated for 235/55R20
IndicatedActual on 235/55R20Actual on 285/35R22Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.4 mph−0.6 mph
75 mph75.0 mph74.2 mph−0.8 mph

Ride-height change: 285/35R22 lowers the vehicle by 0.16 in (4.1 mm) at the axle (half the −8.2 mm diameter difference).

285/35R22 is 0.32 in shorter than 235/55R20 and 50 mm wider, a 1.07% difference in overall diameter.

With the speedometer calibrated for 235/55R20, an indicated 60 mph is actually 59.4 mph on 285/35R22, and revolutions per mile change from 668 to 676.

285/35R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 235/55R20.

Size pages

Other comparisons with 235/55R20

Other comparisons with 285/35R22

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.