Coming to America: the Big 3 consider the U.S. fertile ground to increase passenger diesel market share, but not just yet

Automotive Industries,  May, 2003  by Brent Haight

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In Europe today, conservative numbers put the market penetration of diesel passenger vehicles at over 40 percent, with some individual countries -- France, for example -- seeing as much as 60 percent. At the same time, diesel penetration in the North American passenger vehicle market is less than 1 percent.

Volkswagen has demonstrated a North American interest for diesel vehicles smaller than 8,500 gvw -- it offers diesel versions of its Jetta, Jetta wagon and Golf, with plans to offer diesel New Beetles -- but at this point, it stands alone.

If diesels are so popular in Europe, why then are their numbers practically non existent in North America?

Diesel technology has come a long way from the ill-fated attempts in the 1970s and '80s to introduce diesel passenger cars. Many consumers in North America have a dated image of the loud, "dirty diesels" first offered here by car makers. But those days are long gone. Today, as proven in Europe, diesels are clean and efficient and offer a performance that is unmatched by a gasoline engine.

"Most people don't really have a feel for what modern diesels are like because they haven't experienced them," says Bernard Robertson, senior vice president for engineering technologies and regulatory affairs at DaimlerChrysler. "The major enablers to making diesel engine systems as slick as they are now have been the advances in control systems, the fuel injection systems, the shift to common rail, very high injection pressure and the increasing sophistication of machining of injection nozzles, together with the high pressures to improve atomization.

"There has been dramatic change in the engine control systems," Robertson adds. "I'd say we are at a plateau at the moment, where there are a lot of very slick, refined, pleasant high output diesels which all share, broadly speaking, a similar architecture. The engines are comparable, they are all using high-pressure common rail, they are typically all using pilot injection.

"I think that everyone is now on the cusp of the next significant move which will probably be another increase in injection pressure, another refinement in nozzles, and almost certainly multiple pilot injections instead of one pilot injection."

Gary Smyth, engineering director, GM Power-train, also cited the growing sophistication of diesel technology. "We are now looking at turbocharged with intercoolers with variable geometry turbines," he says. "if you look at the performance, we are now up to 60, 70, 80 hp per liter for those engines."

Though that high-output technology has obviously been successfully demonstrated in Europe, the U.S. still appears to be a few years away from seeing large volumes of under 8,500 gvw diesel vehicles. Besides the daunting task of changing the public's mind, diesels in North America face other challenges, specifically emissions regulations and fuel issues.

Emissions

Looking at the world situation, it should come as no surprise that the European and North American look at the subject of emissions from different perspectives. In Europe, the focus is on reducing CO2. In the U.S. the primary focus is NOx and particulate matter (PM).

In Europe, emissions standards are promulgated through the European Union. In the U.S., the Environmental Protection Agency (EPA) has primary responsibility, but in many cases, follows the lead of the California Air Resources Board (CARB). Because of air quality issues unique to California, CARB has been, in many cases, the tail that wags the emissions dog in North America.

There has been some general movement toward "harmonization" of emissions standards worldwide, but progress toward that goal has not been especially swift. That alone makes it difficult for diesels to freely move between global markets.

"In Europe, when people think clean, they focus on global warming and that is carbon dioxide, which is fuel economy," says John Koszewnik, director of diesel engines at Ford Motor Co. "And there, diesels have a 30 to 40 percent advantage. In the U.S., the clean thought is led by California, and there, they're not so worried about global warming. The C02 they produce goes over the mountain. They're worried about NOx."

"Everyone in the world is working on how to reduce NOx and particulates," adds Robertson. 'The popular approaches to particulates are either further improvements in refinements in engine control to reduce the engine-out particulates combined with very clean fuel, or possibly synthetic diesel fuel or biodiesel fuel. Any of those things seems to have the potential to meet the particulate standards."

Robertson also cites particulate filters to reduce PM, which he says has "obvious merits but also some challenges."

"It is costly," he notes, "and you do have to regenerate. You have to find some way to dispose of the particulates. There is no complete consensus on how to do that successfully. And of course, during the time that you are regenerating the filter, potentially you are emitting something and the EPA requires you to measure that."