205/55R17 vs 225/40R19

Switching from 205/55R17 to 225/40R19 increases the overall diameter by 5.3 mm (0.8%). That is within the usual ±3% guideline.

205/55R17225/40R19Difference (mm / revs)
Section width205 mm225 mm+20.0
Sidewall height112.8 mm90.0 mm-22.8
Rim diameter431.8 mm482.6 mm+50.8
Overall diameter657.3 mm662.6 mm+5.3
Circumference2,065.0 mm2,081.6 mm+16.6
Revolutions484 per km480 per km-4.0

Speedometer effect

With 225/40R19 fitted on a car calibrated for 205/55R17, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.4 km/h
80 km/h80.6 km/h
100 km/h100.8 km/h
120 km/h121.0 km/h

Larger tires make the car go faster than the speedometer shows. Most speedometers also read slightly high from the factory.

Before you change size

205/55R17 dimensions · 225/40R19 dimensions · Open in calculator