Quote Originally Posted by saxman
coasting in gear uses less fuel(assuming you're in a high gear... obviously if you're coasting at 7000rpm this doesn't really apply).

As for if the fuel injectors shut off... think about that. The car is idling... meaning that you're getting combustion in the cylinders. If the fuel injectors are shut off, then there is no fuel injecting into the chamber. No fuel = no combustion = no idling.
Where as if you are rolling in gear, your driveline is connected to the wheels and this motion keeps the engine spinning. Without the aid of the fuel injectors.

Correct??