TireSizesFinder

185/60R15 vs 215/40R17

215/40R17 is 0.03 in (0.8 mm) taller than 185/60R15, a +0.13% diameter difference. With the speedometer set for 185/60R15, an indicated 60 mph is 60.1 mph on 215/40R17.

Is this a safe swap?

Diameter difference +0.13%: under 1%

By overall diameter alone, 215/40R17 is a near match for 185/60R15; 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: 185/60R15 (23.74 in) vs 215/40R17 (23.77 in)185/60R1523.74 in × 7.28 in215/40R1723.77 in × 8.46 in
Side profile and tread width, drawn to the same scale.
185/60R15 vs 215/40R17 differences
Measurement185/60R15215/40R17Difference% diff
Overall diameter23.74 in (603.0 mm)23.77 in (603.8 mm)+0.03 in (+0.8 mm)+0.13%
Sidewall height4.37 in (111.0 mm)3.39 in (86.0 mm)−0.98 in (−25.0 mm)−22.52%
Section width7.28 in (185.0 mm)8.46 in (215.0 mm)+1.18 in (+30.0 mm)+16.22%
Circumference74.58 in (1,894.4 mm)74.68 in (1,896.9 mm)+0.10 in (+2.5 mm)+0.13%
Revolutions per mile850848−1−0.13%
True speed with the speedometer calibrated for 185/60R15
IndicatedActual on 185/60R15Actual on 215/40R17Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 215/40R17 raises the vehicle by 0.02 in (0.4 mm) at the axle (half the +0.8 mm diameter difference).

215/40R17 is 0.03 in taller than 185/60R15 and 30 mm wider, a 0.13% difference in overall diameter.

With the speedometer calibrated for 185/60R15, an indicated 60 mph is actually 60.1 mph on 215/40R17, and revolutions per mile change from 850 to 848.

215/40R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 185/60R15.

Size pages

Other comparisons with 185/60R15

Other comparisons with 215/40R17

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