[Diesel_Dave]

It's hard to pick just one value--it depends on the circumstances. I can think of primarily 3 scenarios.

1) Best case scenario: not at all
This is my goal for any red lights & turns. Ideally, I EOC down to the speed where I can either make the light on green or make the turn. This, however, isn't really an option for stop signs where one must come to a complete stop

2) "Near-ideal" stop sign scenario: 1-5 mph
This is what I consider my ideal scenario for stop signs. I EOC down to about 5 mph, which leaves me just enough energy to consistantly bump start. It also extracts enough energy so that my speed is near-zero and the brakes just barely need touched. This being said, this obviously isn't an option when someone's following you. It also helps a lot to have knowledge of the route to know how to to consistantly glide down to just the right speed.

3) Non-ideal scenario: whatever you have to do
When you're in traffic, of if you mis-time something, then you gotta fo what you gotta do. I would include in this what I call "scrubs"--when I've mis-timed a light it's sometimes beneficial to use the brakes some early on in order to prevent having to come to a complete stop later. The goal tis to preserve as much kinetic energy as possible.

Something else that should be noted is that the "ideal" speed is dependent upon whether one is engine-off or engine-on coasting. If one is engine-off coasting then slower is always better--at least down to the point that you can still bump start. When engine-on coasting there's a break-even speed where the (idle fuel rate)/(vehicle speed) = (target mileage). If vehicle speed decreases further then you start hurting your mileage.

An DFCO is just silly anyway compared to EOC.