Mazda's Smart Idling Stop System

An internal combustion engine that is outfitted with idle-stop technology can save fuel by shutting down the engine when the vehicle stops, and nearly instantly restarting it when the driver takes his foot off the brake pedal. Such technology is common on hybrid cars, but it is starting to appear on non-hybrids too. Usually, it is an electrical motor that restarts the engine by acting like an oversized starter motor. Mazda has developed another way to stop & start an engine: With direct injection technology, fuel is injected directly into the cylinder while the engine is stationary and then ignited to create the downward force necessary to restart the engine (it is actually a bit more complicated than that to get the cylinders in the right position, but that's the general idea). "Mazda claims that the Smart Idling Stop System is more energy-efficient than an electric motor restart, and also restarts the engine more quickly and quietly than a conventional idle-stop system." For more details: ::Green Car Congress