TireSizesFinder

31x10.50R15 vs 245/75R17

245/75R17 is 0.47 in (11.9 mm) taller than 31x10.50R15, a +1.51% diameter difference. With the speedometer set for 31x10.50R15, an indicated 60 mph is 60.9 mph on 245/75R17.

Is this a safe swap?

Diameter difference +1.51%: within the ±3% guideline

By overall diameter alone, 245/75R17 falls inside the ±3% range commonly used as a guideline when replacing 31x10.50R15. 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 245/75R17 (31.47 in)31x10.50R1531.00 in × 10.50 in245/75R1731.47 in × 9.65 in
Side profile and tread width, drawn to the same scale.
31x10.50R15 vs 245/75R17 differences
Measurement31x10.50R15245/75R17Difference% diff
Overall diameter31.00 in (787.4 mm)31.47 in (799.3 mm)+0.47 in (+11.9 mm)+1.51%
Sidewall height8.00 in (203.2 mm)7.23 in (183.8 mm)−0.77 in (−19.4 mm)−9.57%
Section width10.50 in (266.7 mm)9.65 in (245.0 mm)−0.85 in (−21.7 mm)−8.14%
Circumference97.39 in (2,473.7 mm)98.86 in (2,511.1 mm)+1.47 in (+37.4 mm)+1.51%
Revolutions per mile651641−10−1.49%
True speed with the speedometer calibrated for 31x10.50R15
IndicatedActual on 31x10.50R15Actual on 245/75R17Difference
30 mph30.0 mph30.5 mph+0.5 mph
60 mph60.0 mph60.9 mph+0.9 mph
75 mph75.0 mph76.1 mph+1.1 mph

Ride-height change: 245/75R17 raises the vehicle by 0.23 in (5.9 mm) at the axle (half the +11.9 mm diameter difference).

245/75R17 is 0.47 in taller than 31x10.50R15 and 22 mm narrower, a 1.51% difference in overall diameter.

With the speedometer calibrated for 31x10.50R15, an indicated 60 mph is actually 60.9 mph on 245/75R17, and revolutions per mile change from 651 to 641.

245/75R17 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 245/75R17

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