155/80R13 vs 175/65R14

Switching from 155/80R13 to 175/65R14 increases the overall diameter by 4.9 mm (0.8%). That is within the usual ±3% guideline.

155/80R13175/65R14Difference (mm / revs)
Section width155 mm175 mm+20.0
Sidewall height124.0 mm113.8 mm-10.2
Rim diameter330.2 mm355.6 mm+25.4
Overall diameter578.2 mm583.1 mm+4.9
Circumference1,816.5 mm1,831.9 mm+15.4
Revolutions551 per km546 per km-5.0

Speedometer effect

With 175/65R14 fitted on a car calibrated for 155/80R13, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.4 km/h
80 km/h80.7 km/h
100 km/h100.8 km/h
120 km/h121.0 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

155/80R13 dimensions · 175/65R14 dimensions · Open in calculator