TireSizesFinder

255/60R18 vs 235/60R19

235/60R19 is 0.06 in (1.4 mm) taller than 255/60R18, a +0.18% diameter difference. With the speedometer set for 255/60R18, an indicated 60 mph is 60.1 mph on 235/60R19.

Is this a safe swap?

Diameter difference +0.18%: under 1%

By overall diameter alone, 235/60R19 is a near match for 255/60R18; 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: 255/60R18 (30.05 in) vs 235/60R19 (30.10 in)255/60R1830.05 in × 10.04 in235/60R1930.10 in × 9.25 in
Side profile and tread width, drawn to the same scale.
255/60R18 vs 235/60R19 differences
Measurement255/60R18235/60R19Difference% diff
Overall diameter30.05 in (763.2 mm)30.10 in (764.6 mm)+0.06 in (+1.4 mm)+0.18%
Sidewall height6.02 in (153.0 mm)5.55 in (141.0 mm)−0.47 in (−12.0 mm)−7.84%
Section width10.04 in (255.0 mm)9.25 in (235.0 mm)−0.79 in (−20.0 mm)−7.84%
Circumference94.40 in (2,397.7 mm)94.57 in (2,402.1 mm)+0.17 in (+4.4 mm)+0.18%
Revolutions per mile671670−1−0.18%
True speed with the speedometer calibrated for 255/60R18
IndicatedActual on 255/60R18Actual on 235/60R19Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 235/60R19 raises the vehicle by 0.03 in (0.7 mm) at the axle (half the +1.4 mm diameter difference).

235/60R19 is 0.06 in taller than 255/60R18 and 20 mm narrower, a 0.18% difference in overall diameter.

With the speedometer calibrated for 255/60R18, an indicated 60 mph is actually 60.1 mph on 235/60R19, and revolutions per mile change from 671 to 670.

235/60R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 255/60R18.

Size pages

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