TireSizesFinder

175/65R15 vs 215/40R17

215/40R17 is 0.19 in (4.7 mm) shorter than 175/65R15, a −0.77% diameter difference. With the speedometer set for 175/65R15, an indicated 60 mph is 59.5 mph on 215/40R17.

Is this a safe swap?

Diameter difference −0.77%: under 1%

By overall diameter alone, 215/40R17 is a near match for 175/65R15; 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: 175/65R15 (23.96 in) vs 215/40R17 (23.77 in)175/65R1523.96 in × 6.89 in215/40R1723.77 in × 8.46 in
Side profile and tread width, drawn to the same scale.
175/65R15 vs 215/40R17 differences
Measurement175/65R15215/40R17Difference% diff
Overall diameter23.96 in (608.5 mm)23.77 in (603.8 mm)−0.19 in (−4.7 mm)−0.77%
Sidewall height4.48 in (113.8 mm)3.39 in (86.0 mm)−1.09 in (−27.7 mm)−24.40%
Section width6.89 in (175.0 mm)8.46 in (215.0 mm)+1.57 in (+40.0 mm)+22.86%
Circumference75.26 in (1,911.7 mm)74.68 in (1,896.9 mm)−0.58 in (−14.8 mm)−0.77%
Revolutions per mile842848+7+0.78%
True speed with the speedometer calibrated for 175/65R15
IndicatedActual on 175/65R15Actual on 215/40R17Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 215/40R17 lowers the vehicle by 0.09 in (2.4 mm) at the axle (half the −4.7 mm diameter difference).

215/40R17 is 0.19 in shorter than 175/65R15 and 40 mm wider, a 0.77% difference in overall diameter.

With the speedometer calibrated for 175/65R15, an indicated 60 mph is actually 59.5 mph on 215/40R17, and revolutions per mile change from 842 to 848.

215/40R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 175/65R15.

Size pages

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