Changing the Speed Unit from KM/H to MPH

One parameter — P02 — and the two settings people change by mistake instead.
Applies to: D-series
Change Speed Unit from KM/H to MPH — if the player does not load, open the video on YouTube.
The setting
P02 controls the speed unit:
Value
Unit
0
KM/H
1
MPH
Steps
Power on the bike and open the parameter menu (the display's settings entry).
Navigate to P02.
Change the value — 
0 for KM/H, 
1 for MPH.
Save and exit the menu properly.
Power cycle — off, then on.
Confirm the speedo now reads in the unit you chose.
Watch out for
The two adjacent settings are not the speed unit, and changing them causes real problems:
P06 (wheel diameter) — changes speedo accuracy. Set it wrong and the displayed speed is wrong in either unit.
P07 (speed signal magnets) — changes the speedo calibration. Wrong value = wrong speed reading.
If your speedo is reading a plausible but incorrect number, the unit is probably fine and P06/P07 is the real problem. See the P-Setting Guide.
Related
P-Setting Guide
How to Limit Speed
Display & Settings
Tutorials Index