165/70R14 vs 205/45R16

Switching from 165/70R14 to 205/45R16 increases the overall diameter by 4.3 mm (0.7%). That is within the usual ±3% guideline.

165/70R14205/45R16Difference (mm / revs)
Section width165 mm205 mm+40.0
Sidewall height115.5 mm92.2 mm-23.3
Rim diameter355.6 mm406.4 mm+50.8
Overall diameter586.6 mm590.9 mm+4.3
Circumference1,842.9 mm1,856.4 mm+13.5
Revolutions543 per km539 per km-4.0

Speedometer effect

With 205/45R16 fitted on a car calibrated for 165/70R14, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.4 km/h
80 km/h80.6 km/h
100 km/h100.7 km/h
120 km/h120.9 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

165/70R14 dimensions · 205/45R16 dimensions · Open in calculator