D or D Position with D3 Driving Mode
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2014 Honda Ridgeline, 2013 Honda Ridgeline, 2012 Honda Ridgeline, 2011 Honda Ridgeline, and 2010 Honda Ridgeline. 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, 2nd, and 3rd gears (in D with D3 driving mode) according to conditions such as the balance between the throttle opening (engine loading) and vehicle speed.