Diesel Revisited

Photograph by Michael Bailie Will our diesel day come?

While Americans purchase virtually no diesel cars, Europeans buy many, and even an ultracool machine like BMW´s remake of the Mini may join the European diesel brigade. Meanwhile, fuel-economy pressures are making diesels increasingly attractive to U.S. carmakers. Photograph by Michael Bailie

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During the 1980s, A diesel-powered Volkswagen Rabbit was briefly part of my household fleet. It was a particularly frigid Detroit winter, and we had to plug in the Rabbit's engine block heater if we were parked for even an hour or it absolutely refused to start. Even on warm days, our Rabbit hesitated at the touch of the ignition key. Its lack of power necessitated long-term planning for the simplest highway passing maneuvers. The engine clattered, smoked, and smelled like a city bus. The car's sole saving grace was that it traveled miles and miles on a single tank of fuel.

Anyone who has been to Europe recently and rented, say, a BMW 7 Series or a Mercedes-Benz S-Class, or even a Volkswagen Beetle or Ford Focus, knows that today's diesels are far more civilized than our irascible Volkswagen Rabbit. In the past decade, diesel technology has revved ahead. It began with European consumers, who were motivated by gasoline prices at least twice those in the United States. European government officials, meanwhile, concerned about global warming, created tax breaks to encourage diesel car ownership (since diesels burn less fuel, they produce fewer of the greenhouse gases, including carbon dioxide, that contribute to climate change). Automakers responded by investing heavily in diesel research, and the new technologies that emerged have virtually eliminated the smell, noise, and power disadvantage of the diesel. Today, 35 percent of passenger vehicles sold in Europe are diesel-powered, and industry experts predict that portion will rise to 50 percent in the next decade.

In North America, however, only 2 to 3 percent of vehicles sold annually are diesel-powered, according to the Diesel Technology Forum, an industry trade group -- and most of those are commercial vehicles. Diesel is an attractive option for trucks because the fuel savings on gas-guzzling 18-wheelers can be tremendous. When it comes to diesel-powered passenger cars, however, only one is available in the United States: the Volkswagen Golf TDI. That is in part because American consumers, spoiled by cheap gas prices and hampered by enduring negative perceptions, have been down on diesels. In addition, diesel emissions have been specially targeted by U.S. regulators. Diesels spew high levels of nitrogen oxides, gases believed by some experts to be carcinogenic, as well as soot (or particulates), which contribute to the formation of smog. Whereas European pollution standards focus primarily on carbon dioxide emissions and so are achievable by diesel cars, new EPA regulations about to take effect in the United States aim specifically to reduce nitrogen oxides and particulates and will be more difficult for diesel manufacturers to meet.



Nevertheless, automakers are anxious to introduce more diesel-powered models in the United States. That's because SUVs, pickup trucks, and other vehicles that burn through gasoline have been selling so well in recent years, leaving car manufacturers struggling to meet U.S. fuel-economy standards. Those standards are calculated company-wide, which means that fuel-efficient diesels could conveniently offset the gluttony of their more wasteful brethren.

And if the strong sales of the Golf TDI and General Motors' new diesel-powered heavy-duty pickup trucks are any indication, U.S. consumers may be ready. Customers have waited up to six months for delivery of the GM trucks, which are equipped with Duramax diesel engines, and GM is planning to increase production by 50 percent -- to 150,000 diesel engines a year. A shift to diesel could be rather seamless for Detroit automakers, since they are already making diesel-powered vehicles and marketing them elsewhere. Ford, for example, sells a wide range of models abroad, including its economy-size Focus; Chrysler, meanwhile, sells diesel-powered minivans and Jeep Libertys in Europe.



The main appeal of the new diesels, industry proponents say, is that they're not only efficient but fun to drive. "The great success of diesels in Europe comes from much more than simply the engine's fuel economy," says Hermann Scholl, board chairman of Robert Bosch, a German automotive supplier. "The new generation of diesel engines delivers outstanding torque and acceleration -- appealing to people who love to drive."

Rudolf Diesel, a French-born engineer, patented the idea for the diesel engine in 1892. What Diesel invented was an engine that was inherently more fuel-efficient than a gasoline engine. A gasoline engine works by taking in a mixture of gas and air, compressing it, and then igniting the mixture with a spark. A diesel engine, by contrast, takes in only air, compresses it, and then injects fuel into the compressed air. The heat of the compressed air lights the fuel spontaneously. Today's diesels deliver up to 30 percent more fuel economy than do gasoline engines. Diesel fuel, which is heavier and oilier than gasoline, has a higher energy density: A gallon of diesel fuel produces more energy than a gallon of gasoline.