Paging Doctor Diesel

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

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.

What do you think has to take place to bring diesel fuel costs down?

Again, it's a very complex issue. Bosch is not in the fuel business so it is not appropriate for us to speculate. However, the oil industry indicates that adding diesel refinery capacity should reduce the unusual price premium we experience at the moment.

Does Bosch have conversations with the energy companies and car companies about this issue? If so, where is the industry's thinking?

We have talked to the petroleum industry and have been told that the rise of diesel prices is temporary. It is caused by a lack of refining capacity for low-sulfur diesel. We have been told the problem will be solved by 2010 at the latest.

Honda's entrance in the diesel arena with an Acura in 2010 seems like a big deal to me in terms of expanding the audience for diesel, and establishing some street credibility with the uninformed. Do you agree?

Certainly we applaud the entry of new diesel vehicles. This reinforces our belief in the triple-advantage offering of diesel vehicles and their viability for the market. Bosch, like any other auto supplier, cannot comment on behalf of the original equipment manufacturers (OEMs), the companies that originally manufacture automotive products, nor comment on their future plans.

Mahindra & Mahindra is entering the U.S. in 2010 with all diesels for its midsize pickups and SUVs. The company is using Bosch diesel technology. Do you think the manufacturer will have a tough time because it's a new brand, the first brand from India, and all-diesel?

Every new vehicle with a diesel engine will contribute to the goal of reaching an average fuel economy of 35 mpg by 2020. Please understand that we cannot comment on behalf of an OEM. I would simply refer you to Mahindra & Mahindra.

From the standpoint of engine technology, what are the most exciting technological improvements that people can look forward to? For myself, it seems like the biggest advance might be that engines have gotten so much quieter.

To the contrary, there are many exciting and breakthrough tech improvements. Compared with previous common rail systems, that is, a type of diesel fuel injection system, and based on design concepts, the latest generation common rail with piezo-inline technology has the potential to reduce fuel consumption further—lowering emissions, boosting engine power, and reducing engine noise.

And then there's selective catalytic reduction systems (SCRs). This technology assists in removing nitrogen-oxide emissions, enabling diesel vehicles to meet the Environmental Protection Agency's Tier 2 Bin 5 emissions standards. These systems inject a reducing agent, consisting of urea and water, into the exhaust stream. The urea converts into ammonia. And in the second stage in the SCR catalytic converter, the nitrous oxide combines with the ammonia to produce water and harmless nitrogen.

At the center of the SCR system is the Denoxtronic reduction-agent metering system. This system enables nitrogen-oxide emissions to be reduced without adversely affecting efficiency. Customers may see up to 85% lower nitrogen oxide, a fuel savings, and a reduction in CO2 emissions.

How much is Bosch's diesel business growing in the next three to five years?

Globally, Bosch expects to sell 12.5 million high-pressure diesel-injection systems and more than 2 million gasoline direct injection systems this year.

Click here to read more about the new generation of clean diesels coming to a showroom near you.

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