235/60R19 vs 255/60R19

255/60R19 is 0.94 in (24.0 mm) taller than 235/60R19, a +3.14% diameter difference. With the speedometer set for 235/60R19, an indicated 60 mph is 61.9 mph on 255/60R19.

Is this a safe swap?

Diameter difference +3.14%: outside the ±3% guideline

By overall diameter alone, 255/60R19 falls outside the ±3% range commonly used as a guideline when replacing 235/60R19; speedometer and ride-height changes are larger. 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.

235/60R19 vs 255/60R19 differences
Measurement	235/60R19	255/60R19	Difference	% diff
Overall diameter	30.10 in (764.6 mm)	31.05 in (788.6 mm)	+0.94 in (+24.0 mm)	+3.14%
Sidewall height	5.55 in (141.0 mm)	6.02 in (153.0 mm)	+0.47 in (+12.0 mm)	+8.51%
Section width	9.25 in (235.0 mm)	10.04 in (255.0 mm)	+0.79 in (+20.0 mm)	+8.51%
Circumference	94.57 in (2,402.1 mm)	97.54 in (2,477.5 mm)	+2.97 in (+75.4 mm)	+3.14%
Revolutions per mile	670	650	−20	−3.04%

True speed with the speedometer calibrated for 235/60R19
Indicated	Actual on 235/60R19	Actual on 255/60R19	Difference
30 mph	30.0 mph	30.9 mph	+0.9 mph
60 mph	60.0 mph	61.9 mph	+1.9 mph
75 mph	75.0 mph	77.4 mph	+2.4 mph

Ride-height change: 255/60R19 raises the vehicle by 0.47 in (12.0 mm) at the axle (half the +24.0 mm diameter difference).

255/60R19 is 0.94 in taller than 235/60R19 and 20 mm wider, a 3.14% difference in overall diameter.

With the speedometer calibrated for 235/60R19, an indicated 60 mph is actually 61.9 mph on 255/60R19, and revolutions per mile change from 670 to 650.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 235/60R19

Other comparisons with 255/60R19

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