
Originally Posted by
niky
coasting in neutral will only save if you're trying to maintain a high speed. Coasting to a STOP in neutral wastes gas. In most traffic situations, it's better to coast in gear.
The HOLD function on the AT allows it to engine-break. Kung naka-OD or OVERDRIVE, an AT will coast in the highest gear available, and go into neutral/freewheel when below the torque-converter brake point (usually between 2500-3500 rpm). When it's freewheeling, your engine is using a lot of gas to turn the engine crankshaft and torque converter, which weighs between 30-50 pounds... heavy!
But on the highway, you should turn off HOLD or turn on OD so that you can maintain lower rpms at high speed.