245/35R19 vs 255/35R19

Switching from 245/35R19 to 255/35R19 increases the overall diameter by 7.0 mm (1.1%). That is within the usual ±3% guideline.

245/35R19255/35R19Difference (mm / revs)
Section width245 mm255 mm+10.0
Sidewall height85.8 mm89.2 mm+3.4
Rim diameter482.6 mm482.6 mm+0.0
Overall diameter654.1 mm661.1 mm+7.0
Circumference2,054.9 mm2,076.9 mm+22.0
Revolutions487 per km481 per km-6.0

Speedometer effect

With 255/35R19 fitted on a car calibrated for 245/35R19, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.5 km/h
80 km/h80.9 km/h
100 km/h101.1 km/h
120 km/h121.3 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

245/35R19 dimensions · 255/35R19 dimensions · Open in calculator