I like to use the "high idle" feature when I'm going to be idling for extended periods of time. The higher revs help put more oil thru turbo to keep it better lubricated. To use the high idle, turn your cruise control on, while in park just hit the set button to activate the cruise control as if you were driving on the freeway. The engine RPM's should increase a little. to deactivate, just step on the break peddle.