255/40R22 vs 275/40R22

275/40R22 is 0.63 in (16.0 mm) taller than 255/40R22, a +2.10% diameter difference. With the speedometer set for 255/40R22, an indicated 60 mph is 61.3 mph on 275/40R22.

Is this a safe swap?

Diameter difference +2.10%: within the ±3% guideline

By overall diameter alone, 275/40R22 falls inside the ±3% range commonly used as a guideline when replacing 255/40R22. 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.

255/40R22 vs 275/40R22 differences
Measurement	255/40R22	275/40R22	Difference	% diff
Overall diameter	30.03 in (762.8 mm)	30.66 in (778.8 mm)	+0.63 in (+16.0 mm)	+2.10%
Sidewall height	4.02 in (102.0 mm)	4.33 in (110.0 mm)	+0.31 in (+8.0 mm)	+7.84%
Section width	10.04 in (255.0 mm)	10.83 in (275.0 mm)	+0.79 in (+20.0 mm)	+7.84%
Circumference	94.35 in (2,396.4 mm)	96.33 in (2,446.7 mm)	+1.98 in (+50.3 mm)	+2.10%
Revolutions per mile	672	658	−14	−2.05%

True speed with the speedometer calibrated for 255/40R22
Indicated	Actual on 255/40R22	Actual on 275/40R22	Difference
30 mph	30.0 mph	30.6 mph	+0.6 mph
60 mph	60.0 mph	61.3 mph	+1.3 mph
75 mph	75.0 mph	76.6 mph	+1.6 mph

Ride-height change: 275/40R22 raises the vehicle by 0.31 in (8.0 mm) at the axle (half the +16.0 mm diameter difference).

275/40R22 is 0.63 in taller than 255/40R22 and 20 mm wider, a 2.10% difference in overall diameter.

With the speedometer calibrated for 255/40R22, an indicated 60 mph is actually 61.3 mph on 275/40R22, and revolutions per mile change from 672 to 658.

Both sizes mount on 22-inch wheels.

Size pages

Other comparisons with 255/40R22

Other comparisons with 275/40R22

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