And better engines are a big priority. Improving automobiles' fuel economy can reduce both U.S. dependence on foreign oil and the amount of carbon dioxide cars pour into the atmosphere, perhaps slowing global warming. At the same time, government emissions standards for other pollutants produced by burning gasoline are becoming stricter and stricter.

Research into more efficient engines is "more lively [now] than I've ever known it in my 35 years," says Heywood. Founded in 1929, the Sloan lab expanded its research, raised more funding, and experienced a surge of interest in the late 1960s, when cars' contribution to air pollution began to get attention. Research at MIT led to the design of engines with smaller spaces between the piston and the liner, which lowered hydrocarbon emissions. It was in the 1960s that Heywood, then a graduate student studying aerospace propulsion, joined the lab. In 1988, he introduced some of the lab's results into Internal Combustion Engine Fundamentals, a standard reference for engineers. Now the Sloan Lab is part of the newly formed Laboratory for 21st-Century Energy, in which it joins groups performing basic and applied energy research in other areas.

Industrial partners Ford Motor, DaimlerChrysler, General Motors, ExxonMobil, and Delphi are part of the lab's Energy and Fuels Research Consortium, which examines such issues as how fuel vaporizes at different temperatures and how unvaporized fuel travels through an engine. The Oil and Lubrication Research Consortium, meanwhile, has funding from other partners to study the role of friction in engine performance.

John DeCicco, a senior fellow with the environmental group Environmental Defense in Washington, DC, says work by the Sloan lab has helped focus the debate over the role automobiles play in producing greenhouse gases. In particular, he cited "On the Road in 2020," the lab's 2000 report analyzing a variety of engine and fuel technologies. A follow-up study released this March found that hydrogen fuel cells may not offer any advantage over the improved hybrid engines that should be available by the time fuel cells are ready for market.

"It's become almost the definitive study," DeCicco says. "It really was so thorough, and it exercised a very comprehensive methodology. And that just reflects the research and the depth at MIT."