TireSizesFinder

245/50R17 vs 235/40R19

235/40R19 is 0.24 in (6.2 mm) shorter than 245/50R17, a −0.92% diameter difference. With the speedometer set for 245/50R17, an indicated 60 mph is 59.5 mph on 235/40R19.

Is this a safe swap?

Diameter difference −0.92%: under 1%

By overall diameter alone, 235/40R19 is a near match for 245/50R17; 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: 245/50R17 (26.65 in) vs 235/40R19 (26.40 in)245/50R1726.65 in × 9.65 in235/40R1926.40 in × 9.25 in
Side profile and tread width, drawn to the same scale.
245/50R17 vs 235/40R19 differences
Measurement245/50R17235/40R19Difference% diff
Overall diameter26.65 in (676.8 mm)26.40 in (670.6 mm)−0.24 in (−6.2 mm)−0.92%
Sidewall height4.82 in (122.5 mm)3.70 in (94.0 mm)−1.12 in (−28.5 mm)−23.27%
Section width9.65 in (245.0 mm)9.25 in (235.0 mm)−0.39 in (−10.0 mm)−4.08%
Circumference83.71 in (2,126.2 mm)82.94 in (2,106.8 mm)−0.77 in (−19.5 mm)−0.92%
Revolutions per mile757764+7+0.92%
True speed with the speedometer calibrated for 245/50R17
IndicatedActual on 245/50R17Actual on 235/40R19Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.3 mph−0.7 mph

Ride-height change: 235/40R19 lowers the vehicle by 0.12 in (3.1 mm) at the axle (half the −6.2 mm diameter difference).

235/40R19 is 0.24 in shorter than 245/50R17 and 10 mm narrower, a 0.92% difference in overall diameter.

With the speedometer calibrated for 245/50R17, an indicated 60 mph is actually 59.5 mph on 235/40R19, and revolutions per mile change from 757 to 764.

235/40R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 245/50R17.

Size pages

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