225/55R19 vs 225/65R17

Switching from 225/55R19 to 225/65R17 decreases the overall diameter by 5.8 mm (0.8%). That is within the usual ±3% guideline.

225/55R19225/65R17Difference (mm / revs)
Section width225 mm225 mm+0.0
Sidewall height123.8 mm146.2 mm+22.4
Rim diameter482.6 mm431.8 mm-50.8
Overall diameter730.1 mm724.3 mm-5.8
Circumference2,293.7 mm2,275.5 mm-18.2
Revolutions436 per km439 per km+3.0

Speedometer effect

With 225/65R17 fitted on a car calibrated for 225/55R19, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.6 km/h
80 km/h79.4 km/h
100 km/h99.2 km/h
120 km/h119.0 km/h

Smaller tires make the speedometer read higher than the actual speed. Most speedometers also read slightly high from the factory.

Before you change size

225/55R19 dimensions · 225/65R17 dimensions · Open in calculator