Cars don't need to have their engines running when they're stopped at red lights. That's why a number of automakers have developed start-stop systems, which stop a car's engine when the vehicle comes to a halt, and start it again as soon as the gas pedal is pressed. Bosch, however, is taking things farther. Its new start-stop system shuts the engine off not only at stops, but also whenever the car is coasting.
Putting it simply, the "start-stop system with coasting mode" turns off the engine whenever the vehicle can maintain its present speed by rolling. In other words, if the driver's foot isn't on the gas or brake pedals, the engine is off. A simple touch of either pedal causes the engine to instantly start back up.
According to Bosch, tests carried out by the company indicate that most vehicles could coast for about one third of every trip. If the engine was shut off for those periods, it would result in fuel savings of about 10 percent. Additionally, Bosch claims that if every new car sold in Germany were equipped with the system, "the theoretical annual reduction in CO2 would amount to over 30,000 metric tons" (33,069 tons).
What's more, with the engine off, the decreased mechanical resistance should allow cars to coast for longer distances than would otherwise be possible.
The system can reportedly be added to almost any type of existing combustion engine (including hybrids), and requires the installation of relatively few additional parts. It can even be added to cars with manual transmissions, if Bosch's eClutch is also used – this disengages the clutch whenever the vehicle is in coasting mode.
There's no word on availability or pricing of the system, although it is described as "affordable."