As DragTimes points out, Firmware 7.0 for the Tesla Model S brings a new Insane Mode option (as well as Autopilot, of course):

"The latest software version 7 has a new option for Insane mode which allows you to condition the battery for Max Power."

In an effort to see if Max Power made the Model S quicker off the line or if it reduced its quarter-miles times, naturally the folks at DragTimes hit the track:

"This test was done with Max Power in the ready state. There appears to be no notable difference in the acceleration numbers when comparing version 7 to version 6.2. 0-60 MPH was 3.08, 0-100 MPH was 8.31 and 1/4 mile was 11.63 @ 114.9 MPH"