D or L Position
WARNING: This page is about a different car, the 2008 Acura TL and 2007 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
In D, the optimum gear is automatically selected from the 1st, 2nd, 3rd, 4th, and 5th gears (in D); 1st and 2nd gears (in L) according to conditions such as the balance between the throttle opening (engine loading) and vehicle speed.