TireSizesFinder

31x10.50R15 vs 235/75R17

235/75R17 is 0.12 in (3.1 mm) shorter than 31x10.50R15, a −0.39% diameter difference. With the speedometer set for 31x10.50R15, an indicated 60 mph is 59.8 mph on 235/75R17.

Is this a safe swap?

Diameter difference −0.39%: under 1%

By overall diameter alone, 235/75R17 is a near match for 31x10.50R15; 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: 31x10.50R15 (31.00 in) vs 235/75R17 (30.88 in)31x10.50R1531.00 in × 10.50 in235/75R1730.88 in × 9.25 in
Side profile and tread width, drawn to the same scale.
31x10.50R15 vs 235/75R17 differences
Measurement31x10.50R15235/75R17Difference% diff
Overall diameter31.00 in (787.4 mm)30.88 in (784.3 mm)−0.12 in (−3.1 mm)−0.39%
Sidewall height8.00 in (203.2 mm)6.94 in (176.3 mm)−1.06 in (−26.9 mm)−13.26%
Section width10.50 in (266.7 mm)9.25 in (235.0 mm)−1.25 in (−31.7 mm)−11.89%
Circumference97.39 in (2,473.7 mm)97.01 in (2,464.0 mm)−0.38 in (−9.7 mm)−0.39%
Revolutions per mile651653+3+0.40%
True speed with the speedometer calibrated for 31x10.50R15
IndicatedActual on 31x10.50R15Actual on 235/75R17Difference
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: 235/75R17 lowers the vehicle by 0.06 in (1.6 mm) at the axle (half the −3.1 mm diameter difference).

235/75R17 is 0.12 in shorter than 31x10.50R15 and 32 mm narrower, a 0.39% difference in overall diameter.

With the speedometer calibrated for 31x10.50R15, an indicated 60 mph is actually 59.8 mph on 235/75R17, and revolutions per mile change from 651 to 653.

235/75R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 31x10.50R15.

Size pages

Other comparisons with 31x10.50R15

Other comparisons with 235/75R17

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