Not Your Daddy’s Diesel

The mention of diesel to most Americans conjures up unpleasant memories: breathing foul fumes behind a bus or watching black plumes billow from big rigs on the highway.

Despite the fuel’s lowly image, U.S. auto makers are laying the groundwork to put millions of diesel engines into sport-utility vehicles, pickup trucks and other passenger vehicles for the sake of fuel economy over the next decade.

Auto makers, engine suppliers, oil companies and the federal government are intensifying research into diesel, despite growing concerns over the fuel’s effects on air quality and health.

Detroit isn’t looking to sell you your daddy’s diesels--the noisy, sluggish, soot-spewing contraptions of two decades ago. Today’s diesels are much improved, with lower emissions and perky but quiet performance.

In the engine labs of auto makers across the industrial Midwest, there is a certain awe about the diesel. Unlike some other alternative-fuel engines, diesels are held in high esteem by engineers, who see them as rugged, durable and, well, masculine.

More important, they are up to 30% more fuel-efficient than their gasoline cousins, and there are more improvements in the offing. Further engine refinements, cleaner fuels and better catalysts could put to rest diesel’s dirty legacy, proponents say.

Still, the plan to bring back diesels is sparking a heated environmental debate from California to Washington. Diesel’s fuel efficiency produces fewer greenhouse gas emissions, mainly the carbon dioxide linked to global warning. But the engines also release smog-producing emissions and particulates that are suspected of causing cancer.

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As a result, the federal government has conflicting approaches toward diesels: While one agency investigates whether diesel is a cause of cancer, another office is underwriting millions of dollars in diesel research on behalf of the auto industry.

“Diesel highlights the tension between air quality and greenhouse gas goals,” said Daniel Sperling, head of the Institute for Transportation Studies at UC Davis.

Although Detroit likes to wrap itself in a green flag of environmental responsibility, the auto makers’ recent infatuation with diesel engines has more to do with the bottom line than an Earth-first epiphany.

General Motors, Ford and Chrysler are having difficulty meeting federal efficiency standards--known as corporate average fuel economy, or CAFE--for light trucks, their most profitable vehicles.

The Big Three auto makers see diesel engines as the quickest way to improve fuel economy in their gas-guzzlers for the least investment. This would allow them to continue selling high-profit light trucks while avoiding potentially costly CAFE fines and bad publicity.

Diesels could also help the United States comply with the international global-warming agreement reached last year in Kyoto, Japan.

“The push to diesels is driven by CAFE and Kyoto,” said Rod Tabaczynsky, director of Ford’s engine research laboratory. “In my opinion, there’s a high probability that diesels will make a comeback.”

But before the “dieselization” of America revs up, significant hurdles must be overcome, including pollution, cost and image issues.

Diesels emit more nitrous oxides and soot than gas-burning engines. Nitrous oxide is a precursor to smog, and particulates in soot are linked to a variety of health problems, including possibly lung cancer.

Engine makers claim that new technologies can drastically curb diesel’s harmful emissions. Skeptics, however, point out that emissions standards for diesels will get increasingly tougher starting in 2004.

Diesel engines also cost significantly more than their gas brethren. A light-duty diesel engine carries a premium of about $1,000, and even auto officials admit they are unlikely to achieve cost parity with gas engines. The cost premium is offset somewhat by the durability of diesel engines.

The biggest obstacle, however, is whether U.S. consumers will take a shine to diesels given their sordid past in this country.

Twenty years ago, auto makers made a big push with diesel cars to meet fuel economy regulations instituted after the Arab oil embargo in 1973. Sales increased 40% in 1980, and optimistic market forecasters predicted diesel engines would capture 25% of the U.S. car market. That never happened. It topped out at 6% in 1981. Today, fewer than 1% of passenger vehicles on the nation’s roads are diesels.

There are several reasons. Diesels were smelly, noisy and slow. GM hit the market with Oldsmobiles equipped with a converted gas engine that burned diesel fuel. The engine was a lemon. Class-action lawsuits ensued, and GM abandoned the diesel car market in 1986.

“GM set diesels back a long time,” said Dan Ustian, vice president of engine business for Navistar, a major diesel engine manufacturer.

Selling the American public again on diesels will be a chore, he acknowledges. But he argues that recent advances in diesel technology are so dramatic that even reluctant consumers can be won over.

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Diesels are already popular in parts of Asia and Europe, where about 25% of new cars come with diesel engines. Of course, diesel fuel is subsidized in Europe, making it cheaper than high-priced gasoline. In the U.S., diesel fuel is about the same price as gas.

The diesel engine was patented in 1892 by German engineer Rudolf Diesel. Unlike a gas engine that relies on spark ignition, the diesel uses heat and high compression to initiate combustion in its cylinders. The result is more efficient burning of fuel, resulting in greater fuel economy.

Newer diesels use advanced electronic engine-control devices and sensors that monitor the combustion process and optimize the fuel-to-air ratio for greater efficiency. They also use direct injection--precise high-pressure spraying of fuel into the combustion chamber. This enhances efficiency, reduces certain emissions and calms the clatter typical of older diesels.

Another diesel engine advance is “common rail” fuel delivery that allows consistent fuel-injection pressures, giving diesel-powered vehicles better acceleration while reducing emissions, vibration and noise.

“Advanced diesels are much quieter, cleaner and responsive,” said Charles McClure, president of Detroit Diesel, which expects strong growth in the light-duty diesel market in the next decade.

Already Audi, Mercedes-Benz and BMW are selling turbocharged V-8 diesels in luxury cars in Europe that feature the direct-injection and common-rail fuel technologies.

The U.S. Big Three, which also sell diesels in Europe, vow not to be left behind. The proposed $40-billion merger of Chrysler with Daimler-Benz, parent of Mercedes, should boost Chrysler’s efforts to produce more diesel passenger vehicles in the near future.

The three American auto makers all have extensive diesel programs and are working together on diesels under the Partnership for a New Generation of Vehicles, a joint industry-government effort to develop prototype affordable cars by 2004 that get 80 miles per gallon.

With the blessing of the Clinton Administration last year, the partnership consortium identified the diesel engine as a prime technology in meeting the fuel economy goals. Each of the auto makers has shown prototypes of cars powered by hybrid diesel-electric engines.

The National Research Council, however, in its yearly review of the partnership program, recently expressed doubt that technological hurdles in meeting future emissions standards can be overcome. It also pointed out that the diesel hybrids are unlikely to be affordable any time soon.

The partnership’s focus on diesels has infuriated environmentalists.

Jason Mark, a transportation analyst for the Union of Concerned Scientists, calls the diesel engine “air-quality-challenged” and argues that public dollars would be better spent on newer, more promising technologies, such as fuel cells.

Frank O’Donnell, director of the Clean Air Trust, said the choice of diesel for future vehicles puts the issues of fuel economy and air quality on an unnecessary collision course.

“There is no need to make that kind of choice when there are other promising technologies without dangerous trade-offs on the shelf,” he said.

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Last July, Vice President Al Gore endorsed diesels as the best short-term solution to boost fuel economy in the nation’s auto fleet. But under pressure from environmentalists, he backpedaled, saying diesels must meet the same emissions standards as future gas engines. This would require an 80% reduction in nitrous oxide and 50% fewer particulate emissions.

“We cannot use them without solving the emissions problem,” Gore said.

California is taking a similar stance. John Dunlap, chairman of the California Air Resources Board, said diesels make up only 2% of the state’s vehicles but account for 30% of nitrous oxide and 60% of particulate emissions from vehicles.

The agency is drafting tighter emissions standards that will be phased in beginning in 2004. It is expected that diesels will have to meet the same or tougher standards than gasoline engines by then.

“For diesel light-duty vehicles, it means they will have to meet our standards--without exception, without exemption,” Dunlap said.

Diesels are also facing greater scrutiny because of growing concern that the exhaust fumes they release are a health hazard, causing various respiratory ailments, perhaps including lung cancer.

Scientists have debated the dangers of diesel exhaust for 20 years without reaching a consensus. But a draft report released in March by the U.S. Environmental Protection Agency termed diesel exhaust a “probable human carcinogen.” Last month, a panel of scientists told California regulators that diesel emissions are a serious cancer danger and should be regulated as a toxic substance.

Industry officials question these assertions, noting that most of the findings are based on exposures of animals to unusually high levels of diesel.

Despite the health and pollution concerns, the federal government is proposing to spend $44 million on new diesel research this year. That’s on top of $166 million allocated last year for a cooperative effort with engine manufacturers to develop diesels for sport-utility vehicles and pickup trucks.

These efforts come as light trucks, which include sport-utility vehicles, are riding a wave of popularity, accounting for nearly half of all new-vehicle sales. But some SUVs get less than 15 miles per gallon, making it increasingly difficult for auto makers to meet the 20.7 mpg CAFE standard.

Each of the Big Three auto makers has fallen below the CAFE standards for light trucks in recent years, avoiding fines only through legal loopholes that allow them “credits” from previous years.

The government’s interest in diesels is focused on a reduction of greenhouse gases. The Kyoto accord requires the United States to drastically reduce carbon dioxide emissions by 2010.

Auto makers have teamed up not only with the government but also with engine suppliers and the oil industry to produce advanced diesels that are much cleaner and efficient than anything on the road today. They are taking a holistic approach that looks at improving the engine, fuel and catalysts.

The Big Three argue that the fuel itself is a key to cleaner diesel engines. GM has teamed with Amoco and Ford with Mobil to explore the development of reformulated or alternative fuels. Diesel is a less-refined derivative of petroleum than gasoline, but it has a higher energy content.

The auto makers are pushing for a more refined diesel with less sulfur in an effort to improve performance of catalytic converters. The oil industry already produces such a cleaner diesel for California, but it argues that doing so nationwide would be too costly.

However, Jim Katzer, vice president of technology for Mobil, expects to see a gradual improvement in diesel fuel with increased investment in refining and infrastructure nationwide. “The investment can be done over time and is not a major impediment,” he said.

The partners are also looking at more exotic fuels developed from methanol and natural gas, as well as synthetic fuels, that could be burned in diesels.

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Even as research advances, the Big Three are placing bets on light-duty diesels. Ford is working closely with Navistar, which already produces a diesel engine for the auto maker’s largest F-Series pickups. It is likely to add diesels to smaller pickups and SUVs in a few years.

GM already equips some full-size pickups and two-door SUVs with diesel engines. It is working closely with joint venture partner Isuzu on future light-duty diesels and is considering building a diesel engine plant in Moraine, Ohio, capable of building 400,000 engines a year.

Chrysler last year introduced several diesel engines for the European market. It already sells a Dodge Ram pickup with a diesel supplied by Cummins Engine and is looking to extend diesels to other vehicles.

“We see a future for diesels,” said Bernard Robertson, Chrysler’s vice president of engineering technologies. “We expect they will be offered in more and more light vehicles in the near future.”

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Bottomed Out?

Diesel car sales in the United States peaked in 1981 at 520,788 units, before dropping precipitously. Today, diesel cars make up less than 1% of the market, but the Big Three are planning a major campaign to sell diesel cars to meet fuel economy standards. U.S. dealer sales of new diesel cars, in thousands of units:

‘96: 8.5

‘88: Mercedes-Benz stopped production of most U.S.-version diesel cars in 1988 because of a problem with an emissions-control device.

Source: Ward’s Automotive yearbook