[Diesel_Dave]

In my opinion, the notion that fuel-cutoff is the holy grail is one of the biggest falicies out there in hypermiling. While it is true that you're not using any fuel at the moment, the engine is providing a considerable drag on the vehicle (hence the term "engine braking"). That drag is going to slow your vehicle down and you're going to have to make up for it later. The ideal of course is engine off in neutral, but in some cases even idling in neutral is better than motoring with fuel-cutoff.