185/60R14 vs 195/50R15

Switching from 185/60R14 to 195/50R15 decreases the overall diameter by 1.6 mm (0.3%). That is within the usual ±3% guideline.

185/60R14195/50R15Difference (mm / revs)
Section width185 mm195 mm+10.0
Sidewall height111.0 mm97.5 mm-13.5
Rim diameter355.6 mm381.0 mm+25.4
Overall diameter577.6 mm576.0 mm-1.6
Circumference1,814.6 mm1,809.6 mm-5.0
Revolutions551 per km553 per km+2.0

Speedometer effect

With 195/50R15 fitted on a car calibrated for 185/60R14, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.9 km/h
80 km/h79.8 km/h
100 km/h99.7 km/h
120 km/h119.7 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

185/60R14 dimensions · 195/50R15 dimensions · Open in calculator