205/75R15 vs 235/55R17

235/55R17 is 0.07 in (1.8 mm) taller than 205/75R15, a +0.26% diameter difference. With the speedometer set for 205/75R15, an indicated 60 mph is 60.2 mph on 235/55R17.

Is this a safe swap?

Diameter difference +0.26%: under 1%

By overall diameter alone, 235/55R17 is a near match for 205/75R15; 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: 205/75R15 (27.11 in) vs 235/55R17 (27.18 in)205/75R1527.11 in × 8.07 in235/55R1727.18 in × 9.25 in
Side profile and tread width, drawn to the same scale.
205/75R15 vs 235/55R17 differences
Measurement205/75R15235/55R17Difference% diff
Overall diameter27.11 in (688.5 mm)27.18 in (690.3 mm)+0.07 in (+1.8 mm)+0.26%
Sidewall height6.05 in (153.8 mm)5.09 in (129.3 mm)−0.96 in (−24.5 mm)−15.93%
Section width8.07 in (205.0 mm)9.25 in (235.0 mm)+1.18 in (+30.0 mm)+14.63%
Circumference85.16 in (2,163.0 mm)85.38 in (2,168.6 mm)+0.22 in (+5.7 mm)+0.26%
Revolutions per mile744742−2−0.26%
True speed with the speedometer calibrated for 205/75R15
IndicatedActual on 205/75R15Actual on 235/55R17Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.2 mph+0.2 mph
75 mph75.0 mph75.2 mph+0.2 mph

Ride-height change: 235/55R17 raises the vehicle by 0.04 in (0.9 mm) at the axle (half the +1.8 mm diameter difference).

235/55R17 is 0.07 in taller than 205/75R15 and 30 mm wider, a 0.26% difference in overall diameter.

With the speedometer calibrated for 205/75R15, an indicated 60 mph is actually 60.2 mph on 235/55R17, and revolutions per mile change from 744 to 742.

235/55R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 205/75R15.

Size pages

Other comparisons with 205/75R15

Other comparisons with 235/55R17

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