Both the Fusion Hybrid and the C-Max Hybrid can cruise at speeds up to 62mph on batteries alone, with their petrol engine switched off.
After three seconds at a stop light, the engine switches off, as it does in hybrid gasoline-electrics like the Toyota Prius.
Second, it is easy to detect because of its exhaust plume (once the boost phase is over, the engine switches off and the missile follows Newton's law of gravity to its target).
In January, two British Airways Concordes made emergency landings within a 24-hour period, one after an engine switched off, the other after a fire alarm went off in the cockpit.
With the engine switched off, we roll almost silently downhill, peering into the dark green trees, hoping to spot a leopard still on the prowl after a night of instilling fear in the resident bushbuck and impala.
Indeed, one evening our jeep, parked with the engine switched off, is surrounded by a dozen elephants, nudging against the vehicle, trunks nosing almost under our tyres to find clumps of grass, their eyes slowly blinking as they meet ours.
More importantly, it also contains a pair of 60 kilowatt (80 horsepower) electric motors.From a standstill, with the engine switched off, an electric motor at the back of the transmission winds the vehicle up to 30mph provided the driver goes gently on the accelerator pedal.
Once beyond the air, the craft would coast with its engines switched off.
A local newspaper reporter at the scene told the Associated Press that the plane was on the tarmac with its engines switched off, and the local bomb squad had been called.
Then they switch off the engine.
Launched in 1918 from a dolly, it was designed to fly for a fixed length of time, then switch off its engine and jettison its wings, dropping a load of 180 pounds of explosives on its target.
