255/85R16 vs 255/80R17

255/80R17 is 0.00 in (0.1 mm) shorter than 255/85R16, a −0.01% diameter difference. With the speedometer set for 255/85R16, an indicated 60 mph is 60.0 mph on 255/80R17.

Is this a safe swap?

Diameter difference −0.01%: under 1%

By overall diameter alone, 255/80R17 is a near match for 255/85R16; 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.

255/85R16 vs 255/80R17 differences
Measurement	255/85R16	255/80R17	Difference	% diff
Overall diameter	33.07 in (839.9 mm)	33.06 in (839.8 mm)	0.00 in (−0.1 mm)	−0.01%
Sidewall height	8.53 in (216.8 mm)	8.03 in (204.0 mm)	−0.50 in (−12.7 mm)	−5.88%
Section width	10.04 in (255.0 mm)	10.04 in (255.0 mm)	0.00 in (0.0 mm)	0.00%
Circumference	103.88 in (2,638.6 mm)	103.87 in (2,638.3 mm)	−0.01 in (−0.3 mm)	−0.01%
Revolutions per mile	610	610	0	+0.01%

True speed with the speedometer calibrated for 255/85R16
Indicated	Actual on 255/85R16	Actual on 255/80R17
30 mph	30.0 mph	30.0 mph
60 mph	60.0 mph	60.0 mph
75 mph	75.0 mph	75.0 mph

Ride-height change: 255/80R17 lowers the vehicle by 0.00 in (0.1 mm) at the axle (half the −0.1 mm diameter difference).

255/80R17 is the same height as 255/85R16 and the same width, a 0.01% difference in overall diameter.

With the speedometer calibrated for 255/85R16, an indicated 60 mph is actually 60.0 mph on 255/80R17, and revolutions per mile change from 610 to 610.

255/80R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 255/85R16.

Size pages

Other comparisons with 255/85R16

Other comparisons with 255/80R17

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