255/30R22 vs 275/30R22

275/30R22 is 0.47 in (12.0 mm) taller than 255/30R22, a +1.69% diameter difference. With the speedometer set for 255/30R22, an indicated 60 mph is 61.0 mph on 275/30R22.

Is this a safe swap?

Diameter difference +1.69%: within the ±3% guideline

By overall diameter alone, 275/30R22 falls inside the ±3% range commonly used as a guideline when replacing 255/30R22. 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.

255/30R22 vs 275/30R22 differences
Measurement	255/30R22	275/30R22	Difference	% diff
Overall diameter	28.02 in (711.8 mm)	28.50 in (723.8 mm)	+0.47 in (+12.0 mm)	+1.69%
Sidewall height	3.01 in (76.5 mm)	3.25 in (82.5 mm)	+0.24 in (+6.0 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	88.04 in (2,236.2 mm)	89.52 in (2,273.9 mm)	+1.48 in (+37.7 mm)	+1.69%
Revolutions per mile	720	708	−12	−1.66%

True speed with the speedometer calibrated for 255/30R22
Indicated	Actual on 255/30R22	Actual on 275/30R22	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.0 mph	+1.0 mph
75 mph	75.0 mph	76.3 mph	+1.3 mph

Ride-height change: 275/30R22 raises the vehicle by 0.24 in (6.0 mm) at the axle (half the +12.0 mm diameter difference).

275/30R22 is 0.47 in taller than 255/30R22 and 20 mm wider, a 1.69% difference in overall diameter.

With the speedometer calibrated for 255/30R22, an indicated 60 mph is actually 61.0 mph on 275/30R22, and revolutions per mile change from 720 to 708.

Both sizes mount on 22-inch wheels.

Size pages

Other comparisons with 255/30R22

Other comparisons with 275/30R22

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