New software from Siemens VDO Automotive in Schwalbach am Taunus, Germany, could boost cars' fuel efficiency by regulating their electricity usage. Seat heaters, navigation systems, and other power-hungry features increase the demands on the alternator and, in turn, the amount of fuel burned. The software, running on the car's various microprocessor units, economizes by briefly siphoning electricity away from low-priority comfort systems, like air-conditioning, and shuttling it to higher-priority safety and driving systems when the car is, for example, speeding up to pass. Siemens researchers, led by electrical engineer Hans Michael Graf, have tested the software in computer simulations and estimate that it can reduce a car's electric-power usage by 70 percent under city driving conditions -- without the driver's noticing a difference in performance or comfort. They expect to complete construction of a demonstration vehicle using the system by early next year.