32x11.50R15 vs 235/85R16

235/85R16 is 0.27 in (6.9 mm) shorter than 32x11.50R15, a −0.85% diameter difference. With the speedometer set for 32x11.50R15, an indicated 60 mph is 59.5 mph on 235/85R16.

Is this a safe swap?

Diameter difference −0.85%: under 1%

By overall diameter alone, 235/85R16 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 235/85R16 (31.73 in)32x11.50R1532.00 in × 11.50 in235/85R1631.73 in × 9.25 in
Side profile and tread width, drawn to the same scale.
32x11.50R15 vs 235/85R16 differences
Measurement32x11.50R15235/85R16Difference% diff
Overall diameter32.00 in (812.8 mm)31.73 in (805.9 mm)−0.27 in (−6.9 mm)−0.85%
Sidewall height8.50 in (215.9 mm)7.86 in (199.8 mm)−0.64 in (−16.2 mm)−7.48%
Section width11.50 in (292.1 mm)9.25 in (235.0 mm)−2.25 in (−57.1 mm)−19.55%
Circumference100.53 in (2,553.5 mm)99.68 in (2,531.8 mm)−0.85 in (−21.7 mm)−0.85%
Revolutions per mile630636+5+0.86%
True speed with the speedometer calibrated for 32x11.50R15
IndicatedActual on 32x11.50R15Actual on 235/85R16Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 235/85R16 lowers the vehicle by 0.14 in (3.4 mm) at the axle (half the −6.9 mm diameter difference).

235/85R16 is 0.27 in shorter than 32x11.50R15 and 57 mm narrower, a 0.85% difference in overall diameter.

With the speedometer calibrated for 32x11.50R15, an indicated 60 mph is actually 59.5 mph on 235/85R16, and revolutions per mile change from 630 to 636.

235/85R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 32x11.50R15.

Size pages

Other comparisons with 32x11.50R15

Other comparisons with 235/85R16

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