195/60R16 vs 255/40R17

255/40R17 is 0.18 in (4.6 mm) shorter than 195/60R16, a −0.72% diameter difference. With the speedometer set for 195/60R16, an indicated 60 mph is 59.6 mph on 255/40R17.

Is this a safe swap?

Diameter difference −0.72%: under 1%

By overall diameter alone, 255/40R17 is a near match for 195/60R16; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

195/60R16 vs 255/40R17 differences
Measurement	195/60R16	255/40R17	Difference	% diff
Overall diameter	25.21 in (640.4 mm)	25.03 in (635.8 mm)	−0.18 in (−4.6 mm)	−0.72%
Sidewall height	4.61 in (117.0 mm)	4.02 in (102.0 mm)	−0.59 in (−15.0 mm)	−12.82%
Section width	7.68 in (195.0 mm)	10.04 in (255.0 mm)	+2.36 in (+60.0 mm)	+30.77%
Circumference	79.21 in (2,011.9 mm)	78.64 in (1,997.4 mm)	−0.57 in (−14.5 mm)	−0.72%
Revolutions per mile	800	806	+6	+0.72%

True speed with the speedometer calibrated for 195/60R16
Indicated	Actual on 195/60R16	Actual on 255/40R17	Difference
30 mph	30.0 mph	29.8 mph	−0.2 mph
60 mph	60.0 mph	59.6 mph	−0.4 mph
75 mph	75.0 mph	74.5 mph	−0.5 mph

Ride-height change: 255/40R17 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.6 mm diameter difference).

255/40R17 is 0.18 in shorter than 195/60R16 and 60 mm wider, a 0.72% difference in overall diameter.

With the speedometer calibrated for 195/60R16, an indicated 60 mph is actually 59.6 mph on 255/40R17, and revolutions per mile change from 800 to 806.

255/40R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 195/60R16.

Size pages

Other comparisons with 195/60R16

Other comparisons with 255/40R17

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.