205/65R16 vs 235/40R19

Switching from 205/65R16 to 235/40R19 decreases the overall diameter by 2.3 mm (0.3%). That is within the usual ±3% guideline.

205/65R16235/40R19Difference (mm / revs)
Section width205 mm235 mm+30.0
Sidewall height133.2 mm94.0 mm-39.2
Rim diameter406.4 mm482.6 mm+76.2
Overall diameter672.9 mm670.6 mm-2.3
Circumference2,114.0 mm2,106.8 mm-7.2
Revolutions473 per km475 per km+2.0

Speedometer effect

With 235/40R19 fitted on a car calibrated for 205/65R16, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h49.8 km/h
80 km/h79.7 km/h
100 km/h99.7 km/h
120 km/h119.6 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

205/65R16 dimensions · 235/40R19 dimensions · Open in calculator