Valeo Electrical Systems

StARS Micro-Hybrid system

The search is on for breakthrough technology leading to fuel efficiency, and for savings of fossil fuels in particular. Any serious innovation contributing to this global effort is worthy and a valuable contribution. Valeo (Créteil, France) has come up with a winning innovation in this arena.

The StARS Micro-Hybrid consists of a belt driven, reversible claw-pole synchronous machine that mounts on any internal combustion engine in place of the conventional alternator, and a separate electronic inverter placed between the machine and the standard 12V battery. The system allows the combustion engine to be turned off automatically when the car stops and the driver holds the brake pedal down, and to be restarted instantaneously when the brake pedal is released in favor of the accelerator. This entire process is completely transparent to the driver and passengers, except that there is of course no engine sound at all, nor exhaust, while stopped. The StARS Micro-Hybrid can be fitted to both gasoline and diesel engines, with little or no specific design change or adaptation to a particular engine. It’s applicable to any engine without further design modifications, a powerful premise.

The consumer benefits are, obviously, that with the engine automatically shut down when the vehicle comes to a temporary stop, and restarted only when the driver decides to proceed, there is a marked reduction in both fuel consumption and engine emissions, especially in urban and suburban traffic with heavy start-stop demands. And there’s no sound.

Initial commercial applications and uptake of the StARS Micro-Hybrid have been on smaller platforms, but this innovation is now being fitted to larger ones as well, e.g. a 4.2 liter 6-cylinder SUV. It is currently available as an option on the Citroën C3 Sensodrive, with a fuel saving of 6 to 20% in real life urban driving. Citroën’s C2 is on its way, and half dozen other OEM brands have this innovation in development now.