Paging Doctor Diesel

An interview with Johannes-Joerg Rueger, vice-president of engineering for diesel systems at Robert Bosch

By David Kiley

Robert Bosch is a major supplier of diesel technology to automakers such as Mercedes-Benz (DAI), General Motors (GM), and Mahindra & Mahindra (MAHM). The German company, which has U.S. offices in Farmington Hills, Mich., supplies fuel injection systems, sensors, fuel and exhaust management systems, and so on. Perhaps its most important products these days are the systems that trap pollutants from low-sulfur diesel fuel before they get into the atmosphere, making the exhaust from these vehicles often cleaner than the air people breathe in parts of Arizona and California—and certainly in Beijing. It's pretty tough, in fact, to make a diesel-powered vehicle today without buying something from Bosch. Johannes-Joerg Rueger, vice-president of engineering for diesel systems at Bosch, spoke recently with senior correspondent David Kiley about the state and future of diesel vehicles in the U.S.

What projections have you made about the growth of diesel vehicles in the U.S.?

As concerns grow about the environment, fuel economy, and the dependence on petroleum, clean diesel technology provides an alternative for consumers and automakers. Bosch estimates the North American market for light-duty diesel vehicles will reach 15% by 2015. That estimate reflects several elements. Clean diesel passenger vehicles are being introduced this year that meet emissions standards in all 50 states.

According to the Diesel Technology Forum and other news sources, diesel-powered vehicles in the U.S. from BMW (BMWG), Mercedes-Benz, and Volkswagen (VOWG) will soon be joined by clean diesel vehicles from several other automakers, including Acura, Audi (NSUG), Chrysler, Mitsubishi (MMTOF), Nissan (NSANY), Honda (HMC), Hyundai (HYMLF), Toyota (TM), Ford (F), and GM.

In addition, car buyers—especially environmentally conscious ones—are expected to appreciate that on average their diesel vehicles get approximately 30% better fuel economy, 50% more torque, all while emitting about 25% less emissions than comparable gasoline-powered engines with port-fuel injection.

Is that changing at all to reflect the disparity between diesel and regular gas at the pumps. The economics of diesels seems to be evaporating, though the emissions with the new engines and fuel economy are still advantages.

Clearly, fuel-price fluctuation is a complex issue with far-reaching impact. Bosch is not in the fuel business, so we don't feel it's appropriate for us to speculate on the current issue, but we continue to monitor the situation. With our experience of diesel in Europe where ultra-low-sulfur fuel has been introduced first, there was no recognizable impact on the diesel fuel price. Offering a triple advantage of fuel economy, reduced emissions, and driving performance, we believe clean diesel vehicles are a viable choice for consumers, and for automakers who strive to meet the 2020 CAFE [Corporate Average Fuel Economy] requirement of 35 mpg. The CAFE requirements are part of a larger energy bill passed in December 2007.