Bosch start/stop technology is being fitted to more and more passenger cars. From the early part of next year, Fiat will fit its first model to feature a start/stop system: the Fiat 500. Bosch supplies the specially adapted starter, the engine management system, and the battery sensor. The company has been manufacturing this start/stop technology since 2007, and has already delivered more than 500,000 starters to BMW and MINI. Stefan Asenkerschbaumer, president of the Bosch Starter Motors and Generators division, believes this market will grow rapidly in the next few years: "In 2008, roughly five percent of all new vehicles in Europe are equipped with a start/stop system. By 2012, we estimate this will be every second newly registered vehicle – most of them with Bosch technology." In the next few months, series production of other cars featuring this Bosch technology will start, including the Kia cee'd, for example.

Test drives by Bosch engineers indicate that start/stop systems reduce fuel consumption, and thus also CO2 emissions, in the New European Driving Cycle (NEDC) by up to five percent. In the urban component of the NEDC, the saving can be as high as eight percent. Start/stop systems automatically stop the engine when the vehicle is stationary, for example at traffic lights. The engine is restarted as soon as the driver depresses the clutch pedal to select a gear. As starter-based systems are largely based on existing components, their cost-benefit ratio is excellent. And unlike other technologies, this approach is also suitable for cold starts in diesel engines.

In the Fiat 500, the system will initially be available in combination with the Dualogic automated manual transmission and a 1.2-litre engine. Fiat plans to install the system in other variants and models in 2009. Bosch has adjusted the service life of the starter to cope with the far greater number of starts. Its powerful electric starter motor as well as low-noise, enhanced meshing mechanics guarantee safe, fast, and quiet engine starts in all situations. Bosch also supplies the engine control unit for the Fiat 500, including the software used to analyze all the relevant sensor data and to stop and start the engine. In addition, the battery sensor is also supplied by Bosch. It computes the current state of battery charge and relays this information to the energy management system.

Bosch start/stop systems can draw on the expertise of the company's starter technology, drivetrain, and energy management fields. Next to the starter, the control software, and a battery sensor, the system as a whole includes a crankshaft sensor and the respective sensors at the pedals. A high efficiency alternator in combination with a deep-cycle resistant battery means that the amount of time the vehicle can remain stationary with the engine switched off is increased.