205/65R16 vs 215/55R17

Switching from 205/65R16 to 215/55R17 decreases the overall diameter by 4.6 mm (0.7%). That is within the usual ±3% guideline.

205/65R16215/55R17Difference (mm / revs)
Section width205 mm215 mm+10.0
Sidewall height133.2 mm118.2 mm-15.0
Rim diameter406.4 mm431.8 mm+25.4
Overall diameter672.9 mm668.3 mm-4.6
Circumference2,114.0 mm2,099.5 mm-14.5
Revolutions473 per km476 per km+3.0

Speedometer effect

With 215/55R17 fitted on a car calibrated for 205/65R16, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.7 km/h
80 km/h79.5 km/h
100 km/h99.3 km/h
120 km/h119.2 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

205/65R16 dimensions · 215/55R17 dimensions · Open in calculator