TireSizesFinder

225/75R17 vs 255/55R19

255/55R19 is 0.24 in (6.2 mm) shorter than 225/75R17, a −0.81% diameter difference. With the speedometer set for 225/75R17, an indicated 60 mph is 59.5 mph on 255/55R19.

Is this a safe swap?

Diameter difference −0.81%: under 1%

By overall diameter alone, 255/55R19 is a near match for 225/75R17; 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: 225/75R17 (30.29 in) vs 255/55R19 (30.04 in)225/75R1730.29 in × 8.86 in255/55R1930.04 in × 10.04 in
Side profile and tread width, drawn to the same scale.
225/75R17 vs 255/55R19 differences
Measurement225/75R17255/55R19Difference% diff
Overall diameter30.29 in (769.3 mm)30.04 in (763.1 mm)−0.24 in (−6.2 mm)−0.81%
Sidewall height6.64 in (168.8 mm)5.52 in (140.3 mm)−1.12 in (−28.5 mm)−16.89%
Section width8.86 in (225.0 mm)10.04 in (255.0 mm)+1.18 in (+30.0 mm)+13.33%
Circumference95.15 in (2,416.8 mm)94.38 in (2,397.3 mm)−0.77 in (−19.5 mm)−0.81%
Revolutions per mile666671+5+0.81%
True speed with the speedometer calibrated for 225/75R17
IndicatedActual on 225/75R17Actual on 255/55R19Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 255/55R19 lowers the vehicle by 0.12 in (3.1 mm) at the axle (half the −6.2 mm diameter difference).

255/55R19 is 0.24 in shorter than 225/75R17 and 30 mm wider, a 0.81% difference in overall diameter.

With the speedometer calibrated for 225/75R17, an indicated 60 mph is actually 59.5 mph on 255/55R19, and revolutions per mile change from 666 to 671.

255/55R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 225/75R17.

Size pages

Other comparisons with 225/75R17

Other comparisons with 255/55R19

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