245/75R16 vs 265/65R17

Switching from 245/75R16 to 265/65R17 increases the overall diameter by 2.4 mm (0.3%). That is within the usual ±3% guideline.

245/75R16265/65R17Difference (mm / revs)
Section width245 mm265 mm+20.0
Sidewall height183.8 mm172.2 mm-11.6
Rim diameter406.4 mm431.8 mm+25.4
Overall diameter773.9 mm776.3 mm+2.4
Circumference2,431.3 mm2,438.8 mm+7.5
Revolutions411 per km410 per km-1.0

Speedometer effect

With 265/65R17 fitted on a car calibrated for 245/75R16, the real speed when the speedometer shows:

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

245/75R16 dimensions · 265/65R17 dimensions · Open in calculator