265/65R17 vs 265/70R16

Switching from 265/65R17 to 265/70R16 increases the overall diameter by 1.1 mm (0.1%). That is within the usual ±3% guideline.

265/65R17265/70R16Difference (mm / revs)
Section width265 mm265 mm+0.0
Sidewall height172.2 mm185.5 mm+13.3
Rim diameter431.8 mm406.4 mm-25.4
Overall diameter776.3 mm777.4 mm+1.1
Circumference2,438.8 mm2,442.3 mm+3.5
Revolutions410 per km409 per km-1.0

Speedometer effect

With 265/70R16 fitted on a car calibrated for 265/65R17, the real speed when the speedometer shows:

Speedometer showsActual speed
50 km/h50.1 km/h
80 km/h80.1 km/h
100 km/h100.1 km/h
120 km/h120.2 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

265/65R17 dimensions · 265/70R16 dimensions · Open in calculator