To change the cruising speed

See also:

Fuel
Use of a fuel which is low in quality or use of an inappropriate fuel additive may cause engine damage. ...

START
The engine is started in this position. The starter cranks the engine to start it. When the key is released (after the engine has started), the key automatically returns to the “ON” position. ...

Automatic climate control system (if equipped)
NOTE Operate the automatic climate control system when the engine is running. ...