235/35R19 vs 285/30R19

285/30R19 is 0.26 in (6.5 mm) taller than 235/35R19, a +1.00% diameter difference. With the speedometer set for 235/35R19, an indicated 60 mph is 60.6 mph on 285/30R19.

Is this a safe swap?

Diameter difference +1.00%: within the ±3% guideline

By overall diameter alone, 285/30R19 falls inside the ±3% range commonly used as a guideline when replacing 235/35R19. 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.

235/35R19 vs 285/30R19 differences
Measurement	235/35R19	285/30R19	Difference	% diff
Overall diameter	25.48 in (647.1 mm)	25.73 in (653.6 mm)	+0.26 in (+6.5 mm)	+1.00%
Sidewall height	3.24 in (82.3 mm)	3.37 in (85.5 mm)	+0.13 in (+3.3 mm)	+3.95%
Section width	9.25 in (235.0 mm)	11.22 in (285.0 mm)	+1.97 in (+50.0 mm)	+21.28%
Circumference	80.04 in (2,032.9 mm)	80.84 in (2,053.3 mm)	+0.80 in (+20.4 mm)	+1.00%
Revolutions per mile	792	784	−8	−0.99%

True speed with the speedometer calibrated for 235/35R19
Indicated	Actual on 235/35R19	Actual on 285/30R19	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 285/30R19 raises the vehicle by 0.13 in (3.3 mm) at the axle (half the +6.5 mm diameter difference).

285/30R19 is 0.26 in taller than 235/35R19 and 50 mm wider, a 1.00% difference in overall diameter.

With the speedometer calibrated for 235/35R19, an indicated 60 mph is actually 60.6 mph on 285/30R19, and revolutions per mile change from 792 to 784.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 235/35R19

Other comparisons with 285/30R19

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