The following article is from our May 2006 issue.

From the Car, a Whiff of Fries. Diesel engine gains new popularity in America. By Uwe Siemon-Netto

Gasoline prices in the United States are expected to reach $4 per gallon this summer. Suddenly, Volkswagen and Mercedes cars with sturdy and economical diesel engines are beginning to sell furiously in the U.S. And more and more farmers rejoice at the prospect of a turnaround in their fortune. Once economically depressed, they are now joining the ranks of Middle Eastern oil sheikhs - by growing soybeans that can be turned into biodiesel.

A strange thing happened to this reporter after checking out of the quaint Munro Hotel in Jonesville, Mich. There was Kelly, the landlord's prospective daughter-in-law, slipping into her gleaming black Volkswagen Golf. As she started its diesel engine, the vehicle's exhaust pipe filled the air with a distinct whiff of French fries, just like any greasy spoon in a shopping mall.

Later, Kelly explained that she was running her car on biodiesel. "It costs me next to nothing," she said. "I am making it myself in my basement." Kelly collected used cooking oil from a local hamburger joint, filtered it and then, in a simple chemical process, removed its glycerin content, which could be composted or turned into soap or sold to the cosmetics industry.

But Kelly was only interested in what remained - a cheap and safe fuel for her car, a fuel; moreover, it is much less noxious than diesel made from petroleum. Entertainer and songwriter Willie Nelson, America's most celebrated biodiesel aficionado, once quipped that you could drive a car powered by that liquid into your garage, allow the garage's automatic door to close, keep the motor running, fall asleep at the wheel and then wake up the next morning very much alive - just five pounds heavier.

There is a curious irony about biodiesel, whose industrial production in the United States has risen from a mere 25 million gallons in 2004 to 75 million in 2005 and will doubtless reach 200 million gallons next year: it's old hat. While only 41 percent of all Americans are currently familiar with its existence - and that is already a considerable jump from 27 percent the previous year, according to the National Biodiesel Board in Jefferson City, Mo. - it has been around for almost as long as the Diesel engine itself.

In 1892, Rudolf Christian Karl Diesel (1858-1913), a Paris-born Bavarian, received a patent in Berlin for this amazingly durable motor that is now named after him. Eleven years later, he made it run on peanut oil, and that worked very well. But in those days, fuel refined from petroleum was much cheaper. So at least in the United States, the option of nourishing one's car with the fruit of the land fell into oblivion until the big oil crunch of the 1970s almost changed everything.

Suddenly, even Detroit built sedans with fuel-efficient diesel engines, which until then had been the prerogative of certain Mercedes-Benz cars, some of which American eccentrics had been driving about the country for years. The diesel-powered Cadillacs and Oldsmobiles weren't very good, which is why Americans quickly returned to their gas-guzzlers as soon as the crisis was over.

Still, Volkswagen came out with a nice little diesel-powered Rabbit that soon found fans in the United States. One day back in the late 1970s, The Wall Street Journal regaled its readers with the front-page tale about an upstate New York oddball who ran his Rabbit (called Golf today) on grease from the local McDonald's. He was, in a sense, Kelly's predecessor, and his Volkswagen produced precisely the same pong as hers.

Of course, McDonald's restaurants cannot be expected to be the most likely successors of Arab sheikhs. But farmers like Roy Gaesser from Corning, Iowa, might just fit that description. On 50 percent of his sizable holdings, Gaesser now plants soybeans, out of whose oil a local manufacturer produces biodiesel. He told The Atlantic Times in a telephone interview that he was confident the advent of biodiesel would "improve the economic outlook of American farmers considerably."

Not that this kind of fuel will ever by itself be able to fully replace gasoline or diesel made from petroleum. That distinction will probably go to hydrogen. Even in Europe where much more use is made of renewable fuels than in the United States, their share of the market will reach 5.75 percent by the year 2010, according to guidelines set by the European Parliament.

In Germany, where biodiesel can be bought at 1,900 filling stations, as opposed to 700 in the United States, economists have warned that there is simply not nearly enough land around to ever produce enough of that fuel to meet the nation's demand for diesel fuel. It takes one acre of rapeseed - Europe's principal source of biodiesel - to generate 137 gallons of fuel per year, according to the German edition of Technology Review.

But something curious is happening in the United States. In the past, any old diesel car could, after some minor modifications, run on 100 percent pure biodiesel. But the warranties for the latest diesel versions of Volkwagen's Jetta, Golf or New Beatle models only allow for fuel containing up to 5 percent biodiesel. The same applies to the Mercedes E 320 CDI, the only diesel model Daimler Benz currently exports to America.

Volkswagen, Daimler Benz and DaimlerChrysler's Jeep division are at this moment the only manufacturers selling new diesel cars in the U.S.A., and they are going fast and furious because "diesel engines typically offer 45 percent to 60 percent better fuel economy than gasoline engines," according to a report issued by the Massachusetts state government.

Volkswagen of America reports that its diesel-powered Jetta TDI does 41 miles per gallon on the open highway, compared with 30 mpg achieved by a Jetta with a gasoline engine. VW spokeswoman Marijke Smith told The Atlantic Times that some drivers managed to get up to 50 mpg out or their diesel Jettas.

In Europe, there are even less thirsty cars on the market. Daimler Benz' tiny but very comfortable two-seater Smart Diesel, which is the rage of Paris, achieves a fuel efficiency of 60 to 70 mpg. But it has still not been decided whether the U.S. market will ever accept such a pram-like vehicle.

That diesel-driven cars have a significant future in America nobody in the industry doubts. "Why else would BMW, Toyota, General Motors and Honda be scrambling to develop diesels compatible to U.S. emission standards that will come into effect next year?" asked a spokeswoman for Daimler Benz in Germany rhetorically.

These new emission standards are one reason why Volkswagen und Daimler do not certify their latest diesel-powered models for the use of pure biodiesel. But also, they concentrate on designing very sophisticated engines for a new generation of powerful fuels called "sun diesel," which will be made from all sorts of biogenic matter, such as woodchips. "Sun diesel" will be available "in a very few years' time," Daimler Benz spokeswoman Eva Wiese said.

Meanwhile, in Hawaii, the age of pure biodiesel has long reached a new dimension, never mind company warranties. On the island of Maui, you can rent brand-new Volkswagens from the Bio-Beetle Corporation, whose owners Shaun Stenshol, formerly of Greenpeace, and Pamela Miedtke-Wolf not only permit their clients to fill up their cars with biodiesel but actually insist they do so.

"We also have a rental agency at Los Angeles Airport. Should our customers run out of fuel, we will not allow them to go to the regular diesel pump at a filling station. We prefer to bring our fuel to them."

And where does he buy his fuel? From the Pacific Biodiesel Corporation on Maui, which converts the used cooking oil from the multitude of local restaurants into diesel. And has Stenshol ever had any problems with his brand-new cars using that liquid? "Not once," he replied. Moreover, while on the American continent, biodiesel is more expensive than diesel and diesel is costlier than gasoline, the opposite is true on Maui. There, biodiesel costs $2.59 per gallon, compared with $3.52 for unleaded gasoline and $3.80 for "regular" diesel.

This quirky company on an island far away in the Pacific, has indirectly sired a big baby down in Texas, America's quintessential oil state. Annie Nelson, Willie Nelson's wife, was so impressed with Stenshol's Beetles that she asked her husband to buy her a car compatible with biodiesel. "Why?" Willie Nelson asked. She explained. So he promptly became a partner in a corporation that produces biodiesel. It now bears his name, the Willie Nelson Biodiesel Company.

And now whenever Nelson goes on a tour with his bus plus a fleet of companion vehicles, they all run on B20, a fuel containing 20 percent Biodiesel, homemade by his firm.

- Uwe Siemon-Netto, a veteran German foreign correspondent and Lutheran lay theologian, is scholar in residence at Concordia Seminary, St. Louis, MO.