Sure - it makes plenty of sense. Think about it - at a stop light, you have the the auto tranny engaged in drive and your foot is on the pedal. Obviously there is a small load on the entire drivetrain that would be eliminated by putting the transmission into neutral. RPM's will drop slightly. I have no idea what savings is realized at the fuel pump; it probably varies by driver and type of driving. Not worth doing in my book. If I'm going to shift, I'll get a car with a manual transmission.