275/60R17 vs 255/65R17

255/65R17 is 0.06 in (1.5 mm) taller than 275/60R17, a +0.20% diameter difference. With the speedometer set for 275/60R17, an indicated 60 mph is 60.1 mph on 255/65R17.

Is this a safe swap?

Diameter difference +0.20%: under 1%

By overall diameter alone, 255/65R17 is a near match for 275/60R17; 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.

275/60R17 vs 255/65R17 differences
Measurement	275/60R17	255/65R17	Difference	% diff
Overall diameter	29.99 in (761.8 mm)	30.05 in (763.3 mm)	+0.06 in (+1.5 mm)	+0.20%
Sidewall height	6.50 in (165.0 mm)	6.53 in (165.8 mm)	+0.03 in (+0.8 mm)	+0.45%
Section width	10.83 in (275.0 mm)	10.04 in (255.0 mm)	−0.79 in (−20.0 mm)	−7.27%
Circumference	94.22 in (2,393.3 mm)	94.41 in (2,398.0 mm)	+0.19 in (+4.7 mm)	+0.20%
Revolutions per mile	672	671	−1	−0.20%

True speed with the speedometer calibrated for 275/60R17
Indicated	Actual on 275/60R17	Actual on 255/65R17	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.1 mph	+0.1 mph
75 mph	75.0 mph	75.1 mph	+0.1 mph

Ride-height change: 255/65R17 raises the vehicle by 0.03 in (0.8 mm) at the axle (half the +1.5 mm diameter difference).

255/65R17 is 0.06 in taller than 275/60R17 and 20 mm narrower, a 0.20% difference in overall diameter.

With the speedometer calibrated for 275/60R17, an indicated 60 mph is actually 60.1 mph on 255/65R17, and revolutions per mile change from 672 to 671.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 275/60R17

Other comparisons with 255/65R17

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