VW's hyperfuturistic concept car gets 100km/l.
The automated gearbox is coupled to a start-stop system, which includes a freewheel function. In overrun mode, the vehicle switches the engine off. The vehicle then rolls without the engine running. Development engineers call this gliding — alluding to the silent flight of a glider. The engine starts up again immediately when the magnesium accelerator pedal is depressed. A specially developed starter-alternator makes sure the engine is immediately restarted. Positioned between the engine and gearbox and using a dual clutch system, this works as both current generator and flywheel. In gliding mode, both clutches are open. When the driver presses the accelerator pedal again, the clutch between the engine and the starter-alternator is closed, causing the still turning flywheel to restart the engine without consuming any electrical current. Apart from this, the crankshaft starter-alternator, which eliminates the need for a conventional alternator and starter motor, has a so-called boost function which is able to supply additional power to supplement the power of the engine. But that is not all the starter-alternator does. While braking, the negative acceleration energy is fed into the alternator and recovered (recuperation).
(Thanks, Jens!)
