215/45R18 vs 245/35R19

Switching from 215/45R18 to 245/35R19 increases the overall diameter by 3.4 mm (0.5%). That is within the usual ±3% guideline.

215/45R18245/35R19Difference (mm / revs)
Section width215 mm245 mm+30.0
Sidewall height96.8 mm85.8 mm-11.0
Rim diameter457.2 mm482.6 mm+25.4
Overall diameter650.7 mm654.1 mm+3.4
Circumference2,044.2 mm2,054.9 mm+10.7
Revolutions489 per km487 per km-2.0

Speedometer effect

With 245/35R19 fitted on a car calibrated for 215/45R18, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.3 km/h
80 km/h80.4 km/h
100 km/h100.5 km/h
120 km/h120.6 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

215/45R18 dimensions · 245/35R19 dimensions · Open in calculator