TireSizesFinder

265/55R19 vs 235/55R20

235/55R20 is 0.30 in (7.6 mm) shorter than 265/55R19, a −0.98% diameter difference. With the speedometer set for 265/55R19, an indicated 60 mph is 59.4 mph on 235/55R20.

Is this a safe swap?

Diameter difference −0.98%: under 1%

By overall diameter alone, 235/55R20 is a near match for 265/55R19; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 265/55R19 (30.48 in) vs 235/55R20 (30.18 in)265/55R1930.48 in × 10.43 in235/55R2030.18 in × 9.25 in
Side profile and tread width, drawn to the same scale.
265/55R19 vs 235/55R20 differences
Measurement265/55R19235/55R20Difference% diff
Overall diameter30.48 in (774.1 mm)30.18 in (766.5 mm)−0.30 in (−7.6 mm)−0.98%
Sidewall height5.74 in (145.8 mm)5.09 in (129.3 mm)−0.65 in (−16.5 mm)−11.32%
Section width10.43 in (265.0 mm)9.25 in (235.0 mm)−1.18 in (−30.0 mm)−11.32%
Circumference95.74 in (2,431.9 mm)94.80 in (2,408.0 mm)−0.94 in (−23.9 mm)−0.98%
Revolutions per mile662668+7+0.99%
True speed with the speedometer calibrated for 265/55R19
IndicatedActual on 265/55R19Actual on 235/55R20Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.4 mph−0.6 mph
75 mph75.0 mph74.3 mph−0.7 mph

Ride-height change: 235/55R20 lowers the vehicle by 0.15 in (3.8 mm) at the axle (half the −7.6 mm diameter difference).

235/55R20 is 0.30 in shorter than 265/55R19 and 30 mm narrower, a 0.98% difference in overall diameter.

With the speedometer calibrated for 265/55R19, an indicated 60 mph is actually 59.4 mph on 235/55R20, and revolutions per mile change from 662 to 668.

235/55R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 265/55R19.

Size pages

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