TireSizesFinder

255/45R18 vs 285/35R19

285/35R19 is 0.18 in (4.6 mm) shorter than 255/45R18, a −0.67% diameter difference. With the speedometer set for 255/45R18, an indicated 60 mph is 59.6 mph on 285/35R19.

Is this a safe swap?

Diameter difference −0.67%: under 1%

By overall diameter alone, 285/35R19 is a near match for 255/45R18; 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: 255/45R18 (27.04 in) vs 285/35R19 (26.85 in)255/45R1827.04 in × 10.04 in285/35R1926.85 in × 11.22 in
Side profile and tread width, drawn to the same scale.
255/45R18 vs 285/35R19 differences
Measurement255/45R18285/35R19Difference% diff
Overall diameter27.04 in (686.7 mm)26.85 in (682.1 mm)−0.18 in (−4.6 mm)−0.67%
Sidewall height4.52 in (114.8 mm)3.93 in (99.8 mm)−0.59 in (−15.0 mm)−13.07%
Section width10.04 in (255.0 mm)11.22 in (285.0 mm)+1.18 in (+30.0 mm)+11.76%
Circumference84.93 in (2,157.3 mm)84.37 in (2,142.9 mm)−0.57 in (−14.5 mm)−0.67%
Revolutions per mile746751+5+0.67%
True speed with the speedometer calibrated for 255/45R18
IndicatedActual on 255/45R18Actual on 285/35R19Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.5 mph−0.5 mph

Ride-height change: 285/35R19 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.6 mm diameter difference).

285/35R19 is 0.18 in shorter than 255/45R18 and 30 mm wider, a 0.67% difference in overall diameter.

With the speedometer calibrated for 255/45R18, an indicated 60 mph is actually 59.6 mph on 285/35R19, and revolutions per mile change from 746 to 751.

285/35R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 255/45R18.

Size pages

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