Quote Originally Posted by Triathlete View Post
The power mode simply changes your shift points. The engine revs a little higher allowing more line pressure to build giving a little crisper shifting...or something like that...
This is my interpretation of what happens when the "Power" button is used also. More horsepower is produced higher in the rpm range of the engine, so changing the shift-points of the trans allows the driver to take advantage of those engine characteristics (for towing, passing, etc), although whether those shift points coincide with engine redline probably depends on individual variations from stock rim/tire sizes.