The Myth: I can save fuel by letting my car idle for short periods rather then turning it off and on again.

The Evidence: Ten seconds of idling can use more fuel than turning off the engine and restarting it. Excessive idling can actually damage your engine components, including cylinders, spark plugs, and exhaust systems. Fuel is only partially combusted when idling because an engine does not operate at its peak temperature. This leads to the build up of fuel residues on cylinder walls that can damage engine components and increase fuel consumption.  A good rule of thumb: if you are going to be parked for more than 30 seconds, turn off your engine.  And remember:  Idling gets ZERO miles per gallon.

The Verdict:  False