TireSizesFinder

215/75R15 vs 235/55R17

235/55R17 is 0.52 in (13.2 mm) shorter than 215/75R15, a −1.88% diameter difference. With the speedometer set for 215/75R15, an indicated 60 mph is 58.9 mph on 235/55R17.

Is this a safe swap?

Diameter difference −1.88%: within the ±3% guideline

By overall diameter alone, 235/55R17 falls inside the ±3% range commonly used as a guideline when replacing 215/75R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 215/75R15 (27.70 in) vs 235/55R17 (27.18 in)215/75R1527.70 in × 8.46 in235/55R1727.18 in × 9.25 in
Side profile and tread width, drawn to the same scale.
215/75R15 vs 235/55R17 differences
Measurement215/75R15235/55R17Difference% diff
Overall diameter27.70 in (703.5 mm)27.18 in (690.3 mm)−0.52 in (−13.2 mm)−1.88%
Sidewall height6.35 in (161.3 mm)5.09 in (129.3 mm)−1.26 in (−32.0 mm)−19.84%
Section width8.46 in (215.0 mm)9.25 in (235.0 mm)+0.79 in (+20.0 mm)+9.30%
Circumference87.01 in (2,210.1 mm)85.38 in (2,168.6 mm)−1.63 in (−41.5 mm)−1.88%
Revolutions per mile728742+14+1.91%
True speed with the speedometer calibrated for 215/75R15
IndicatedActual on 215/75R15Actual on 235/55R17Difference
30 mph30.0 mph29.4 mph−0.6 mph
60 mph60.0 mph58.9 mph−1.1 mph
75 mph75.0 mph73.6 mph−1.4 mph

Ride-height change: 235/55R17 lowers the vehicle by 0.26 in (6.6 mm) at the axle (half the −13.2 mm diameter difference).

235/55R17 is 0.52 in shorter than 215/75R15 and 20 mm wider, a 1.88% difference in overall diameter.

With the speedometer calibrated for 215/75R15, an indicated 60 mph is actually 58.9 mph on 235/55R17, and revolutions per mile change from 728 to 742.

235/55R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 215/75R15.

Size pages

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