255/65R16 vs 235/65R17

235/65R17 is 0.02 in (0.6 mm) shorter than 255/65R16, a −0.08% diameter difference. With the speedometer set for 255/65R16, an indicated 60 mph is 60.0 mph on 235/65R17.

Is this a safe swap?

Diameter difference −0.08%: under 1%

By overall diameter alone, 235/65R17 is a near match for 255/65R16; 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: 255/65R16 (29.05 in) vs 235/65R17 (29.03 in)255/65R1629.05 in × 10.04 in235/65R1729.03 in × 9.25 in
Side profile and tread width, drawn to the same scale.
255/65R16 vs 235/65R17 differences
Measurement255/65R16235/65R17Difference% diff
Overall diameter29.05 in (737.9 mm)29.03 in (737.3 mm)−0.02 in (−0.6 mm)−0.08%
Sidewall height6.53 in (165.8 mm)6.01 in (152.8 mm)−0.51 in (−13.0 mm)−7.84%
Section width10.04 in (255.0 mm)9.25 in (235.0 mm)−0.79 in (−20.0 mm)−7.84%
Circumference91.27 in (2,318.2 mm)91.19 in (2,316.3 mm)−0.07 in (−1.9 mm)−0.08%
Revolutions per mile694695+1+0.08%
True speed with the speedometer calibrated for 255/65R16
IndicatedActual on 255/65R16Actual on 235/65R17Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.0 mph0.0 mph
75 mph75.0 mph74.9 mph−0.1 mph

Ride-height change: 235/65R17 lowers the vehicle by 0.01 in (0.3 mm) at the axle (half the −0.6 mm diameter difference).

235/65R17 is 0.02 in shorter than 255/65R16 and 20 mm narrower, a 0.08% difference in overall diameter.

With the speedometer calibrated for 255/65R16, an indicated 60 mph is actually 60.0 mph on 235/65R17, and revolutions per mile change from 694 to 695.

235/65R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 255/65R16.

Size pages

Other comparisons with 255/65R16

Other comparisons with 235/65R17

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