Turns out, your car's engine is useless about a third of the time when you're driving. Bosch is using that math to estimate that the newest generation of its stop-start system could cut a car's overall fuel use by about 10 percent.

Most stop-start systems involved merely shutting off the engine when the vehicle comes to a stop (hence the name), replacing needless idling in the process. The German automotive components giant says its new system shuts down the engine as soon as the foot's taken off the gas pedal, indicating that all coasting can be done engine- and fuel-use-free. The company is also touting the system's faster restarts and says it can be used with gas-, natural gas- or diesel-powered vehicles.

It was reported last month that Ford will expand its stop-start function beyond its 2013 Ford Fusion to larger, more gas-guzzling vehicles like the F-150 pickup. The Blue Oval has estimated that stop-start can save drivers more than $1,000 in refueling costs over five years. Meanwhile, Mercedes-Benz parent Daimler is trying to gain some points with the emissions gods (actually the US Environmental Protection Agency) by claiming that the benefits its stop-start technology has on its fleetwide fuel economy is being underestimated. Daimler is shooting for an additional MPG worth of credit, saying its cars are idle about 24 percent of the time, not the 14 percent estimated by the EPA. Math is fascinating. Check out Bosch's press release below.
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Automotive technology

Start-stop system with coasting mode

New Bosch system stops the engine when the vehicle is traveling at speed, helping cut fuel consumption by 10 percent

Noise-free, zero-emission coasting phases 30 percent of the time

Function can be combined with any type of combustion engine

Economical system cuts CO2 emissions in real traffic conditions

Dr. Rolf Bulander: "Start-stop coasting will become an everyday feature in cars - just like air conditioning."

December 10, 2013

With its new start-stop coasting function, Bosch enables drivers of vehicles with combustion engines to travel in zero-emission, noise-free, and low-resistance mode over large parts of their journey. This innovative technology stops the engine when the vehicle is in motion, so that it does not consume any fuel. Whenever the vehicle can maintain its speed simply by rolling – for instance on a gentle incline – the engine is stopped. As soon as the driver touches the gas or brake pedal, the engine starts up again.

Tests carried out by Bosch have shown that the combustion engines runs needlessly about 30 percent of the time, meaning that the vehicle could simply coast for about a third of every journey. Although these phases are not taken into account in the New European Driving Cycle (NEDC), under real traffic conditions the function will give drivers a roughly 10 percent fuel saving. "The start-stop coasting function is affordable, can be combined with any type of combustion engine, and substantially reduces fuel consumption," says Dr. Rolf Bulander, member of the board of management of Robert Bosch GmbH.

Much of what makes the system innovative is its enhanced software and the use this makes of existing sensor data. Furthermore, the start-stop starter has been configured to cope with greater loads and to deliver faster restarts. In other respects, the system requires few additional components and can be integrated in just about any vehicle in the world. Whether they drive diesel-powered cars in Europe, gasoline models in North America, or CNG-powered vehicles in Asia, drivers everywhere stand to benefit from the new technology – as does the environment. After all, reduced fuel consumption also means lower CO2 emissions. In Germany, some three million new vehicles were sold in 2012. According to statistics, the annual average distance driven is around 11,500 kilometers. If every new car were equipped with the coasting system and emitted just ten grams less CO2 per kilometer as a result, the theoretical annual reduction in CO2 would amount to over 30,000 metric tons.

Soon everybody will be coasting
Today, thanks to double-clutch transmissions, some vehicles already have a "light" version of the coasting system on board. As soon as the drivers take their foot off the gas pedal, the system switches the engine to idle. While this means the vehicle is doing no more than rolling, it is still consuming fuel in order to keep the engine ticking over. Bosch start-stop systems, which have enjoyed success all over the world, stop the vehicle's engine altogether. The first generation of the system stops the engine only when the vehicle is completely stationary, while the enhanced start-stop system cuts the engine as soon as the vehicle is coasting to a halt – for instance at a red light. In contrast, as soon as the driver's foot is off both the gas and the brake pedal, vehicles equipped with the new start-stop coasting function stop the engine while the vehicle is in motion. That saves even more fuel. And because the engine is disengaged, the vehicle can coast for longer than it could with an overrun fuel cutoff system, for example.

"Bosch is confident that start-stop coasting will soon become an everyday feature in cars – just like air conditioning," says Bulander. Bosch is embedding fuel-saving functionality in many of its innovative products. One example is eClutch, which makes it easy to offer the coasting function even in vehicles with manual transmissions. As soon as a coasting phase is possible, eClutch decouples automatically and the engine is stopped. The coasting function is also available as an add-on for the Bosch entry-level hybrid, the boost recuperation system, to help it save even more fuel. Equipped with a more powerful generator and a compact lithium-ion battery, the 48-volt hybrid saves around 15 percent of fuel through electrification alone. In real traffic conditions, and fitted with the coasting function that shuts down the engine, the hybrid can achieve fuel savings of an additional ten percent – or 25 percent overall. The newly developed, economical Bosch start-stop coasting function can operate with any combustion or hybrid engine and thus has a wide range of applications. That is one reason why it was voted "Most Innovative Technology" in the "Green" category at the Dinner for Winners event hosted by German auto industry journal Automobil Produktion.
Automotive Technology is the largest Bosch Group business sector. In 2012, its sales came to 31.1 billion euros, or 59 percent of total group sales. This makes the Bosch Group one of the leading automotive suppliers. Its roughly 177,000 Automotive Technology associates worldwide mainly work in the following areas of business: injection technology for internal-combustion engines, alternative powertrain concepts, efficient and networked powertrain peripherals, systems for active and passive driving safety, assistance and comfort functions, technology for user-friendly infotainment as well as car-to-car and Car2X communication, and concepts, technology, and service for the automotive aftermarket. Bosch has been responsible for important automotive innovations, such as electronic engine management, the ESP® anti-skid system, and common-rail diesel technology.

The Bosch Group is a leading global supplier of technology and services. In fiscal 2012, its roughly 306,000 associates generated sales of 52.5 billion euros. Since the beginning of 2013, its operations have been divided into four business sectors: Automotive Technology, Industrial Technology, Consumer Goods, and Energy and Building Technology. The Bosch Group comprises Robert Bosch GmbH and its roughly 360 subsidiaries and regional companies in some 50 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for further growth. Bosch spent some 4.8 billion euros for research and development in 2012, and applied for nearly 4,800 patents worldwide. The Bosch Group's products and services are designed to fascinate, and to improve the quality of life by providing solutions which are both innovative and beneficial. In this way, the company offers technology worldwide that is "Invented for life."

Further information is available online at www.bosch.com and www.bosch-press.com, http://twitter.com/BoschPresse.

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