Engine Braking and Fuel Economy

[Samson]

Originally Posted by jonnycool

i think i heard that some modern cars fuel supply is cut off under engine braking.

This is true of pretty much all newer cars. No fuel is needed to keep the engine spinning when you are coasting down in gear. When putting it in neutral and coasting, fuel is needed to keep the engine running.
So, you use less fuel if you just coast down to the lights in gear, plus it saves your brakes. Downshifting during this process isn't really necessary on mostly flat ground.