Washington, D.C. -- U.S. auto manufacturers are eyeing light-duty diesel vehicles, which currently make up a minute fraction of vehicle sales here, with growing interest. Despite the challenges of meeting clean air standards and overcoming consumer skepticism, diesel engines' superior efficiency has led a number of companies to pursue new products aggressively. The American Council for an Energy-Efficient Economy (ACEEE) examines the viability of an increase in light-duty diesels in its new report, Deliberating Diesel: Environmental, Technical, and Social Factors Affecting Diesel Passenger Vehicle Prospects in the United States.

"Meeting the new tailpipe standards will be tough for diesels, but probably doable," said report co-author James Kliesch, a Research Associate with ACEEE. "The cost of a diesel will stay substantially higher than the cost of a comparable gasoline vehicle, though—the diesel will take several years to pay for itself unless fuel prices rise dramatically." Light-duty diesel sales in Europe have shot up in recent years, and approached 40 percent in 2002. However, high fuel prices and less stringent emissions requirements make Europe a very different market from the United States. The ACEEE report reviews current and upcoming diesel models in the United States and Europe.

"A shift toward diesel has the potential to lower vehicles' energy consumption by 20 to 30 percent, but that opportunity will be squandered unless manufacturers are pushed to raise average fuel economy," stated Therese Langer, co-author and Director of ACEEE's Transportation Program. "Right now, manufacturers can just use diesels to replace lighter gasoline vehicles or to offset sales of gas guzzlers."

Public health concerns have made the environmental community cautious of growth in the diesel market. While new tailpipe standards apply equally to diesel and gasoline vehicles, the standards do not regulate emissions of the smallest and most dangerous particles, or airborne toxics, both of which are associated with diesel vehicles. Other technologies, including gasoline-electric hybrid vehicles, also offer large energy savings, but without the potential public health penalty associated with diesel technology.

Deliberating Diesel: Environmental, Technical, and Social Factors Affecting Diesel Passenger Vehicle Prospects in the United States (by James Kliesch and Therese Langer) is available for free at http://www.aceee.org/pubs/t032.htm.

For further details, contact ACEEE Publications, 529 14th Street, N.W., Suite 600, Washington, D.C. 20045, phone: 202-507-4000, fax: 202-429-2248, e-mail: aceee_publications@aceee.org.

About ACEEE: The American Council for an Energy-Efficient Economy is an independent, nonprofit organization dedicated to advancing energy efficiency as a means of promoting economic prosperity, energy security,  and environmental protection. For information about ACEEE and its programs, publications, and conferences, contact ACEEE, 529 14th Street N.W., Suite 600, Washington, D.C. 20045 or visit www.aceee.org.