TireSizesFinder

205/50R17 vs 255/30R19

255/30R19 is 0.05 in (1.2 mm) shorter than 205/50R17, a −0.19% diameter difference. With the speedometer set for 205/50R17, an indicated 60 mph is 59.9 mph on 255/30R19.

Is this a safe swap?

Diameter difference −0.19%: under 1%

By overall diameter alone, 255/30R19 is a near match for 205/50R17; 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: 205/50R17 (25.07 in) vs 255/30R19 (25.02 in)205/50R1725.07 in × 8.07 in255/30R1925.02 in × 10.04 in
Side profile and tread width, drawn to the same scale.
205/50R17 vs 255/30R19 differences
Measurement205/50R17255/30R19Difference% diff
Overall diameter25.07 in (636.8 mm)25.02 in (635.6 mm)−0.05 in (−1.2 mm)−0.19%
Sidewall height4.04 in (102.5 mm)3.01 in (76.5 mm)−1.02 in (−26.0 mm)−25.37%
Section width8.07 in (205.0 mm)10.04 in (255.0 mm)+1.97 in (+50.0 mm)+24.39%
Circumference78.76 in (2,000.6 mm)78.61 in (1,996.8 mm)−0.15 in (−3.8 mm)−0.19%
Revolutions per mile804806+2+0.19%
True speed with the speedometer calibrated for 205/50R17
IndicatedActual on 205/50R17Actual on 255/30R19Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.9 mph−0.1 mph
75 mph75.0 mph74.9 mph−0.1 mph

Ride-height change: 255/30R19 lowers the vehicle by 0.02 in (0.6 mm) at the axle (half the −1.2 mm diameter difference).

255/30R19 is 0.05 in shorter than 205/50R17 and 50 mm wider, a 0.19% difference in overall diameter.

With the speedometer calibrated for 205/50R17, an indicated 60 mph is actually 59.9 mph on 255/30R19, and revolutions per mile change from 804 to 806.

255/30R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 205/50R17.

Size pages

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