See also:

Lubrication oil circulation in the refrigerant circuit
Operate the air conditioner compressor at a low engine speed (at idle or low driving speeds) a few minutes each month during the off-season to circulate its oil. ...

Speedometer
The speedometer shows the vehicle speed. ...

Checking the fluid level
The automatic transmission fluid expands largely as its temperature rises; the fluid level differs according to fluid temperature. Therefore, there are two different scales for checking the level ...