After purchasing my 2007 Edge just a couple of weeks ago with 23,000 miles on it, they told me about the overdrive feature. As I drive around Central, PA for work throughout the week I was very interested to know that this was a great feature to turn off when going up and down large hills (which is what most of district consists of). I wasn't used to the dramatic downshifts that are associated with turning O/D off, but it certainly helps with braking down my large hills and mountains especially when poor weather is involved. I was concerned with the high RPM's too, but after doing a little digging online it would seem that this is actually good for the engine instead of running it at low RPM's with overdrive on all of the time. With so many hills and mountains in my area, I consistently have O/D off unless traveling on level ground for extended periods.
