245/75R17 vs 265/75R16

Switching from 245/75R17 to 265/75R16 increases the overall diameter by 4.6 mm (0.6%). That is within the usual ±3% guideline.

245/75R17265/75R16Difference (mm / revs)
Section width245 mm265 mm+20.0
Sidewall height183.8 mm198.8 mm+15.0
Rim diameter431.8 mm406.4 mm-25.4
Overall diameter799.3 mm803.9 mm+4.6
Circumference2,511.1 mm2,525.5 mm+14.4
Revolutions398 per km396 per km-2.0

Speedometer effect

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

Speedometer showsActual speed
50 km/h50.3 km/h
80 km/h80.5 km/h
100 km/h100.6 km/h
120 km/h120.7 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

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