Reducing emissions and improving fuel economy is a huge area of investment for many carmakers. Most people equate this type of technology with hybrid or electric vehicles, but Bosch has a system that helps improve fuel economy and reduce emissions on diesel and gasoline motors as well.
The system is called the Bosch Stop-Start System. Bosch and Fiat announced recently that the Fiat 500 would use the systems and Bosch went so far as to claim that 50% of European vehicles would have the Stop-Start system by 2012.
Bosch has been making the system since 2007 and reports it has already delivered 500,000 of the special starters to BMW and Mini. In the Fiat 500, Bosch says the Stop-Start system would be available with the Dualogic automated manual transmission and the 1.2-liter engine. Fiat does say it plans to install the system on other vehicles as early as 2009.
The Fiat 500 will also use a Bosch engine control unit including Bosch software that analyzes the sensor data to start and stop the engine of the vehicle. Stefan Asenkerschbaumer, president of Bosch Starter Motors and Generators division said, "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."
The Bosch Stop-Start system works by turning the motor of the vehicle off when the vehicle is stationary. An example is if a driver pulled up to a stop light, the Stop-Start system would turn the motor off while at rest. When the driver put a foot on the clutch pedal to put the car back in gear, the engine would start back up.
Bosch says that the system reduces fuel consumption and CO2 emissions in the urban component of the New European Driving Cycle (NEDC) by up to 8%. To ensure that the starter lasts with the significantly increased stop/start cycles, critical components of the special starter have been strengthened. Bosch says it increased the service life of starters used in the Stop-Start system compared to a normal starter. The bearings in the new starter were strengthened, the commutator is strengthened, and the planetary gear was improved as well.
The system has other components including control software, a battery sensor, crankshaft sensor, and sensors at the pedals. A high-efficiency alternator and a deep-cycle electric battery are part of the system.
A few specifics on the system remain unclear. For instance, presumably the system won’t function if the driver doesn't place the vehicle in neutral. Bosch isn't specific on that aspect of the system. Another concern is how long the vehicle will be able to remain with the engine cut off in high power usage scenarios like summer with the air conditioner running or in winter with the heater on.
Bosch doesn’t specify if the system would automatically restart the vehicle if it were still stationary if the battery started to get too low on power. Presumably, the system would restart so the driver won’t be left with a dead battery.