TireSizesFinder

235/40R19 vs 225/35R20

225/35R20 is 0.20 in (5.1 mm) shorter than 235/40R19, a −0.76% diameter difference. With the speedometer set for 235/40R19, an indicated 60 mph is 59.5 mph on 225/35R20.

Is this a safe swap?

Diameter difference −0.76%: under 1%

By overall diameter alone, 225/35R20 is a near match for 235/40R19; 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: 235/40R19 (26.40 in) vs 225/35R20 (26.20 in)235/40R1926.40 in × 9.25 in225/35R2026.20 in × 8.86 in
Side profile and tread width, drawn to the same scale.
235/40R19 vs 225/35R20 differences
Measurement235/40R19225/35R20Difference% diff
Overall diameter26.40 in (670.6 mm)26.20 in (665.5 mm)−0.20 in (−5.1 mm)−0.76%
Sidewall height3.70 in (94.0 mm)3.10 in (78.8 mm)−0.60 in (−15.2 mm)−16.22%
Section width9.25 in (235.0 mm)8.86 in (225.0 mm)−0.39 in (−10.0 mm)−4.26%
Circumference82.94 in (2,106.8 mm)82.31 in (2,090.7 mm)−0.63 in (−16.0 mm)−0.76%
Revolutions per mile764770+6+0.77%
True speed with the speedometer calibrated for 235/40R19
IndicatedActual on 235/40R19Actual on 225/35R20Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 225/35R20 lowers the vehicle by 0.10 in (2.5 mm) at the axle (half the −5.1 mm diameter difference).

225/35R20 is 0.20 in shorter than 235/40R19 and 10 mm narrower, a 0.76% difference in overall diameter.

With the speedometer calibrated for 235/40R19, an indicated 60 mph is actually 59.5 mph on 225/35R20, and revolutions per mile change from 764 to 770.

225/35R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 235/40R19.

Size pages

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