I did the engine off coasting in my automatic for a week or so but since have stopped because the members here and another (altima specific) forum i frequent at have convinced me that there might be damage occurring and I am not going to risk it for a couple of bucks.
http://forum.ecomodder.com/showthrea...53.html?t=1153
You can come to your own conclusion there^ because there are mixed answers.
I guess it depends on the vehicle.