I just recently bought a NAH this last weekend and have been having alot of fun driving it. Like GripperDon, I too am here in Phoenix where we have set a new record today of having 28 days of 110+ degrees! Because it's been hot, of course we use the air conditioner.
Don, one of the things I think I figured out is that the EV mode kicks in better when the AC is not on full-blast. I also have a Pathfinder and when it's hot, I get in and hit the "AUTO" button that blasts the A/C to cool it down to the temperature desired. Because it wasn't as hot this last weekend, I tried a couple of things. First, I made a trip to the store a few miles away with the A/C on high to see about what speed the EV mode would kick in as I slowly decelerated - and it kicked in about the 10-15
mph range. When I got home, I made the same trip (since I had the A/C on full before, the car was pretty much cooled off) with the AC on only the second light setting (about medium) - and the EV kicked in about the 30-35
mph range. It seems to me, and it seems to make sense to me, that the level of air conditioning definitely plays a direct role in ability to drive in the EV mode because of the drain caused by the A/C.
So, if you have your car in a temperature controlled garage, when you leave, try turning your A/C on a lower setting and having the vents blowing directly on you to see if you run in EV mode more often and increase your MPG. Just a suggestion from a (very) newbie.