Since production of Bosch’s start-stop technology began in 2007, one million vehicles have been fitted with the system. On the New European Driving Cycle (NEDC), start-stop systems reduce fuel consumption and CO2 emissions by up to 5 percent, whilst the saving is as much as 8 percent on the NEDC urban cycle.
While only 5 percent of all new vehicles in Europe were equipped with start-stop systems in 2008, Bosch predicts that this will increase to 50 percent by 2012. The Bosch Start-Stop system features in models made by BMW and Mini, Fiat, Kia, and Volkswagen, among others.
“Bosch start-stop systems are excellent value for money, since they are based mainly on already existing components, which are then optimized. This is why start-stop is such a good solution for people who want to drive economically and eco-consciously,” says Dr. Stefan Asenkerschbaumer, president of the Bosch Starter Motors and Generators division.
Start-stop systems stop the engine when the vehicle comes to a halt, for example at a red light or in a traffic jam, starting it again automatically when the clutch is depressed and the vehicle is put back into gear. The Bosch system features a powerful electric starter motor, as well as enhanced meshing mechanics, which guarantee a safe, fast, and quiet engine start.
The system also includes control software, which is generally integrated into the engine ECU, and a battery sensor, which records the current battery charge and relays this information to the energy management system. This ensures that the engine is only stopped if the battery has stored enough energy to start the engine again quickly. The system also features sensors on the crankshaft and pedals, as well as a deep-cycle resistant battery.
New alternator series for even greater fuel savings
For the most seamless start-stop operation, Bosch also offers a new series of alternators. Models in the ‘Efficiency Line’ (EL) series feature improved electrical design and new diodes, and are up to 77 percent efficient. In addition, these alternators ensure that the battery is well charged even when the engine is idling or running at low revolutions. Combining the Bosch Start-Stop system with an EL-series alternator can reduce fuel consumption and CO2 emissions in urban driving by as much as 10 percent.