They also talked to some engineers about the effects of putting the transmission in neutral while coasting and of course shutting off the engine while the car is stopped. That last one is not generally recommended for cars that aren't designed with auto start/stop systems. It puts a lot of extra wear and tear on the starter and lubrication system as well as causing other potential problems. Its also very inconvenient if, like most Americans, you drive an automatic transmission car. At a drive through, for example, you'd probably be better off just parking and walking inside to get your fast food fix. Check out all of Mike's results and, as always, remember that your mileage may vary.
[Source: Car and Driver]