TireSizesFinder

275/35R19 vs 235/35R20

235/35R20 is 0.10 in (2.6 mm) shorter than 275/35R19, a −0.39% diameter difference. With the speedometer set for 275/35R19, an indicated 60 mph is 59.8 mph on 235/35R20.

Is this a safe swap?

Diameter difference −0.39%: under 1%

By overall diameter alone, 235/35R20 is a near match for 275/35R19; 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: 275/35R19 (26.58 in) vs 235/35R20 (26.48 in)275/35R1926.58 in × 10.83 in235/35R2026.48 in × 9.25 in
Side profile and tread width, drawn to the same scale.
275/35R19 vs 235/35R20 differences
Measurement275/35R19235/35R20Difference% diff
Overall diameter26.58 in (675.1 mm)26.48 in (672.5 mm)−0.10 in (−2.6 mm)−0.39%
Sidewall height3.79 in (96.3 mm)3.24 in (82.3 mm)−0.55 in (−14.0 mm)−14.55%
Section width10.83 in (275.0 mm)9.25 in (235.0 mm)−1.57 in (−40.0 mm)−14.55%
Circumference83.50 in (2,120.9 mm)83.18 in (2,112.7 mm)−0.32 in (−8.2 mm)−0.39%
Revolutions per mile759762+3+0.39%
True speed with the speedometer calibrated for 275/35R19
IndicatedActual on 275/35R19Actual on 235/35R20Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.8 mph−0.2 mph
75 mph75.0 mph74.7 mph−0.3 mph

Ride-height change: 235/35R20 lowers the vehicle by 0.05 in (1.3 mm) at the axle (half the −2.6 mm diameter difference).

235/35R20 is 0.10 in shorter than 275/35R19 and 40 mm narrower, a 0.39% difference in overall diameter.

With the speedometer calibrated for 275/35R19, an indicated 60 mph is actually 59.8 mph on 235/35R20, and revolutions per mile change from 759 to 762.

235/35R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 275/35R19.

Size pages

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