175/65R14 vs 185/60R14

Switching from 175/65R14 to 185/60R14 decreases the overall diameter by 5.5 mm (0.9%). That is within the usual ±3% guideline.

175/65R14185/60R14Difference (mm / revs)
Section width175 mm185 mm+10.0
Sidewall height113.8 mm111.0 mm-2.8
Rim diameter355.6 mm355.6 mm+0.0
Overall diameter583.1 mm577.6 mm-5.5
Circumference1,831.9 mm1,814.6 mm-17.3
Revolutions546 per km551 per km+5.0

Speedometer effect

With 185/60R14 fitted on a car calibrated for 175/65R14, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.5 km/h
80 km/h79.2 km/h
100 km/h99.1 km/h
120 km/h118.9 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

175/65R14 dimensions · 185/60R14 dimensions · Open in calculator