155/80R13 vs 165/65R14

Switching from 155/80R13 to 165/65R14 decreases the overall diameter by 8.1 mm (1.4%). That is within the usual ±3% guideline.

155/80R13165/65R14Difference (mm / revs)
Section width155 mm165 mm+10.0
Sidewall height124.0 mm107.2 mm-16.8
Rim diameter330.2 mm355.6 mm+25.4
Overall diameter578.2 mm570.1 mm-8.1
Circumference1,816.5 mm1,791.0 mm-25.5
Revolutions551 per km558 per km+7.0

Speedometer effect

With 165/65R14 fitted on a car calibrated for 155/80R13, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.3 km/h
80 km/h78.9 km/h
100 km/h98.6 km/h
120 km/h118.3 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

155/80R13 dimensions · 165/65R14 dimensions · Open in calculator