215/65R17 vs 235/60R17

Switching from 215/65R17 to 235/60R17 increases the overall diameter by 2.5 mm (0.4%). That is within the usual ±3% guideline.

215/65R17235/60R17Difference (mm / revs)
Section width215 mm235 mm+20.0
Sidewall height139.8 mm141.0 mm+1.2
Rim diameter431.8 mm431.8 mm+0.0
Overall diameter711.3 mm713.8 mm+2.5
Circumference2,234.6 mm2,242.5 mm+7.9
Revolutions448 per km446 per km-2.0

Speedometer effect

With 235/60R17 fitted on a car calibrated for 215/65R17, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.2 km/h
80 km/h80.3 km/h
100 km/h100.4 km/h
120 km/h120.4 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

215/65R17 dimensions · 235/60R17 dimensions · Open in calculator