31x10.50R16 vs 255/70R17

255/70R17 is 0.06 in (1.4 mm) taller than 31x10.50R16, a +0.18% diameter difference. With the speedometer set for 31x10.50R16, an indicated 60 mph is 60.1 mph on 255/70R17.

Is this a safe swap?

Diameter difference +0.18%: under 1%

By overall diameter alone, 255/70R17 is a near match for 31x10.50R16; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

31x10.50R16 vs 255/70R17 differences
Measurement	31x10.50R16	255/70R17	Difference	% diff
Overall diameter	31.00 in (787.4 mm)	31.06 in (788.8 mm)	+0.06 in (+1.4 mm)	+0.18%
Sidewall height	7.50 in (190.5 mm)	7.03 in (178.5 mm)	−0.47 in (−12.0 mm)	−6.30%
Section width	10.50 in (266.7 mm)	10.04 in (255.0 mm)	−0.46 in (−11.7 mm)	−4.39%
Circumference	97.39 in (2,473.7 mm)	97.56 in (2,478.1 mm)	+0.17 in (+4.4 mm)	+0.18%
Revolutions per mile	651	649	−1	−0.18%

True speed with the speedometer calibrated for 31x10.50R16
Indicated	Actual on 31x10.50R16	Actual on 255/70R17	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.1 mph	+0.1 mph
75 mph	75.0 mph	75.1 mph	+0.1 mph

Ride-height change: 255/70R17 raises the vehicle by 0.03 in (0.7 mm) at the axle (half the +1.4 mm diameter difference).

255/70R17 is 0.06 in taller than 31x10.50R16 and 12 mm narrower, a 0.18% difference in overall diameter.

With the speedometer calibrated for 31x10.50R16, an indicated 60 mph is actually 60.1 mph on 255/70R17, and revolutions per mile change from 651 to 649.

255/70R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 31x10.50R16.

Size pages

Other comparisons with 31x10.50R16

Other comparisons with 255/70R17

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.