195/70R14 vs 215/45R17

Switching from 195/70R14 to 215/45R17 decreases the overall diameter by 3.3 mm (0.5%). That is within the usual ±3% guideline.

195/70R14215/45R17Difference (mm / revs)
Section width195 mm215 mm+20.0
Sidewall height136.5 mm96.8 mm-39.7
Rim diameter355.6 mm431.8 mm+76.2
Overall diameter628.6 mm625.3 mm-3.3
Circumference1,974.8 mm1,964.4 mm-10.4
Revolutions506 per km509 per km+3.0

Speedometer effect

With 215/45R17 fitted on a car calibrated for 195/70R14, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.7 km/h
80 km/h79.6 km/h
100 km/h99.5 km/h
120 km/h119.4 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

195/70R14 dimensions · 215/45R17 dimensions · Open in calculator