235/55R17 vs 235/60R16

Switching from 235/55R17 to 235/60R16 decreases the overall diameter by 1.9 mm (0.3%). That is within the usual ±3% guideline.

235/55R17235/60R16Difference (mm / revs)
Section width235 mm235 mm+0.0
Sidewall height129.2 mm141.0 mm+11.8
Rim diameter431.8 mm406.4 mm-25.4
Overall diameter690.3 mm688.4 mm-1.9
Circumference2,168.6 mm2,162.7 mm-5.9
Revolutions461 per km462 per km+1.0

Speedometer effect

With 235/60R16 fitted on a car calibrated for 235/55R17, 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

235/55R17 dimensions · 235/60R16 dimensions · Open in calculator