235/55R19 vs 235/65R17

Switching from 235/55R19 to 235/65R17 decreases the overall diameter by 3.8 mm (0.5%). That is within the usual ±3% guideline.

235/55R19235/65R17Difference (mm / revs)
Section width235 mm235 mm+0.0
Sidewall height129.2 mm152.8 mm+23.6
Rim diameter482.6 mm431.8 mm-50.8
Overall diameter741.1 mm737.3 mm-3.8
Circumference2,328.2 mm2,316.3 mm-11.9
Revolutions430 per km432 per km+2.0

Speedometer effect

With 235/65R17 fitted on a car calibrated for 235/55R19, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.7 km/h
80 km/h79.6 km/h
100 km/h99.5 km/h
120 km/h119.4 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

235/55R19 dimensions · 235/65R17 dimensions · Open in calculator