215/55R17 vs 235/40R19

235/40R19 is 0.09 in (2.3 mm) taller than 215/55R17, a +0.34% diameter difference. With the speedometer set for 215/55R17, an indicated 60 mph is 60.2 mph on 235/40R19.

Is this a safe swap?

Diameter difference +0.34%: under 1%

By overall diameter alone, 235/40R19 is a near match for 215/55R17; 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.

215/55R17 vs 235/40R19 differences
Measurement	215/55R17	235/40R19	Difference	% diff
Overall diameter	26.31 in (668.3 mm)	26.40 in (670.6 mm)	+0.09 in (+2.3 mm)	+0.34%
Sidewall height	4.66 in (118.3 mm)	3.70 in (94.0 mm)	−0.95 in (−24.2 mm)	−20.51%
Section width	8.46 in (215.0 mm)	9.25 in (235.0 mm)	+0.79 in (+20.0 mm)	+9.30%
Circumference	82.66 in (2,099.5 mm)	82.94 in (2,106.8 mm)	+0.28 in (+7.2 mm)	+0.34%
Revolutions per mile	767	764	−3	−0.34%

True speed with the speedometer calibrated for 215/55R17
Indicated	Actual on 215/55R17	Actual on 235/40R19	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.2 mph	+0.2 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 235/40R19 raises the vehicle by 0.05 in (1.1 mm) at the axle (half the +2.3 mm diameter difference).

235/40R19 is 0.09 in taller than 215/55R17 and 20 mm wider, a 0.34% difference in overall diameter.

With the speedometer calibrated for 215/55R17, an indicated 60 mph is actually 60.2 mph on 235/40R19, and revolutions per mile change from 767 to 764.

235/40R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 215/55R17.

Size pages

Other comparisons with 215/55R17

Other comparisons with 235/40R19

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