TireSizesFinder

245/40R18 vs 245/35R19

245/35R19 is 0.04 in (0.9 mm) taller than 245/40R18, a +0.14% diameter difference. With the speedometer set for 245/40R18, an indicated 60 mph is 60.1 mph on 245/35R19.

Is this a safe swap?

Diameter difference +0.14%: under 1%

By overall diameter alone, 245/35R19 is a near match for 245/40R18; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 245/40R18 (25.72 in) vs 245/35R19 (25.75 in)245/40R1825.72 in × 9.65 in245/35R1925.75 in × 9.65 in
Side profile and tread width, drawn to the same scale.
245/40R18 vs 245/35R19 differences
Measurement245/40R18245/35R19Difference% diff
Overall diameter25.72 in (653.2 mm)25.75 in (654.1 mm)+0.04 in (+0.9 mm)+0.14%
Sidewall height3.86 in (98.0 mm)3.38 in (85.8 mm)−0.48 in (−12.2 mm)−12.50%
Section width9.65 in (245.0 mm)9.65 in (245.0 mm)0.00 in (0.0 mm)0.00%
Circumference80.79 in (2,052.1 mm)80.90 in (2,054.9 mm)+0.11 in (+2.8 mm)+0.14%
Revolutions per mile784783−1−0.14%
True speed with the speedometer calibrated for 245/40R18
IndicatedActual on 245/40R18Actual on 245/35R19Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 245/35R19 raises the vehicle by 0.02 in (0.4 mm) at the axle (half the +0.9 mm diameter difference).

245/35R19 is 0.04 in taller than 245/40R18 and the same width, a 0.14% difference in overall diameter.

With the speedometer calibrated for 245/40R18, an indicated 60 mph is actually 60.1 mph on 245/35R19, and revolutions per mile change from 784 to 783.

245/35R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 245/40R18.

Size pages

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Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.