From the 100+ hypermiling tips:
55) Engine off coasting
Engine-off coasting (EOC) is one of the largest contributors to increased efficiency of hybrid vehicles, many of which automatically shut down the engine when the accelerator is released and the vehicle is coasting.
EOC can be accomplished in non-hybrids as well simply by shifting to neutral and switching the key from "Run" to "Acc" (being careful not to switch to "Off" and cause the steering to lock). As soon as the engine stops, return the key to the "Run" position or else you will be in danger of locking out your steering and crashing. Also be careful to not steer at all while the key is off to prevent a lock up.
This technique is best suited to cars with manual steering and manual transmissions. (Dramatically increased steering effort may be required in some cars with power assist. Also, most vehicles with automatic transmissions are not designed to travel with the engine shut off; the transmission may be damaged).
In non-hybrids, EOC is considered an advanced technique and should not be attempted until the skill developed away from traffic. In addition, coasting with the engine off is illegal in some areas.
The best way to EOC is with a kill switch that shuts off the engine without removing the key, thereby eliminating the dangers of locking the steering wheel.
I hope your wife does not ban you from ecomodding
