Delphi Automotive Systems could help increase the urban fuel economy of smaller vehicles by more than 5 percent with its new stop-start system. The technology, dubbed Energen 5, uses a combined starter/alternator in the conventional generator position, allowing the engine to be automatically stopped when the vehicle idles and restarted almost instantaneously when the accelerator is pressed. Compared with conventional in-line stop-start solutions, Energen 5 is quieter, weighs less, has fewer components and requires almost no additional packaging volume. Energen 5 is suitable for gasoline engines up to 1.6 liters and diesels up to 1.2 liters, with either 12-volt or 42-volt architectures and an electrical requirement of up to 5kW. The base system is air cooled, but it also is available with liquid cooling of the starter and electronics. This can provide almost immediate heat to supplement cabin heating and will further reduce emissions by accelerating the rate of engine/catalyst warm-up. Energen is a family of technologies for the generation, distribution and management of electrical energy, which can be tightly integrated with conventional internal combustion engines and powertrains. Larger sizes include an in-line starter-alternator, integrated with the powertrain between the engine and the gearbox, to provide electrical generation, energy recovery, torque damping and power assist for mild hybrid operation. Delphi has demonstrated fuel economy improvements of up to 15 percent on a sport/utility vehicle fitted with the Energen 10 in-line system. Energen 5 recently was demonstrated to customers and journalists at a ride and drive event in the U.S. Delphi expects Energen 5 to enter production for the 2003-model year with at least one major European vehicle manufacturer. A number of other manufacturers in Europe and Asia are also evaluating the technology.