TireSizesFinder

32x11.50R15 vs 255/75R17

255/75R17 is 0.06 in (1.5 mm) taller than 32x11.50R15, a +0.18% diameter difference. With the speedometer set for 32x11.50R15, an indicated 60 mph is 60.1 mph on 255/75R17.

Is this a safe swap?

Diameter difference +0.18%: under 1%

By overall diameter alone, 255/75R17 is a near match for 32x11.50R15; 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: 32x11.50R15 (32.00 in) vs 255/75R17 (32.06 in)32x11.50R1532.00 in × 11.50 in255/75R1732.06 in × 10.04 in
Side profile and tread width, drawn to the same scale.
32x11.50R15 vs 255/75R17 differences
Measurement32x11.50R15255/75R17Difference% diff
Overall diameter32.00 in (812.8 mm)32.06 in (814.3 mm)+0.06 in (+1.5 mm)+0.18%
Sidewall height8.50 in (215.9 mm)7.53 in (191.3 mm)−0.97 in (−24.7 mm)−11.42%
Section width11.50 in (292.1 mm)10.04 in (255.0 mm)−1.46 in (−37.1 mm)−12.70%
Circumference100.53 in (2,553.5 mm)100.72 in (2,558.2 mm)+0.19 in (+4.7 mm)+0.18%
Revolutions per mile630629−1−0.18%
True speed with the speedometer calibrated for 32x11.50R15
IndicatedActual on 32x11.50R15Actual on 255/75R17Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 255/75R17 raises the vehicle by 0.03 in (0.8 mm) at the axle (half the +1.5 mm diameter difference).

255/75R17 is 0.06 in taller than 32x11.50R15 and 37 mm narrower, a 0.18% difference in overall diameter.

With the speedometer calibrated for 32x11.50R15, an indicated 60 mph is actually 60.1 mph on 255/75R17, and revolutions per mile change from 630 to 629.

255/75R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 32x11.50R15.

Size pages

Other comparisons with 32x11.50R15

Other comparisons with 255/75R17

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