175/65R14 vs 205/45R16

Switching from 175/65R14 to 205/45R16 increases the overall diameter by 7.8 mm (1.3%). That is within the usual ±3% guideline.

175/65R14205/45R16Difference (mm / revs)
Section width175 mm205 mm+30.0
Sidewall height113.8 mm92.2 mm-21.6
Rim diameter355.6 mm406.4 mm+50.8
Overall diameter583.1 mm590.9 mm+7.8
Circumference1,831.9 mm1,856.4 mm+24.5
Revolutions546 per km539 per km-7.0

Speedometer effect

With 205/45R16 fitted on a car calibrated for 175/65R14, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.7 km/h
80 km/h81.1 km/h
100 km/h101.3 km/h
120 km/h121.6 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

175/65R14 dimensions · 205/45R16 dimensions · Open in calculator