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To get a sense of the auto industry’s progress in fuel efficiency, look no further than the 2002 Chevy Blazer. The model with automatic transmission, six cylinders, and four-wheel drive gets 18 miles per gallon (mpg), two miles less than a comparably equipped Blazer did in 1985. Indeed, in those 17 years the average fuel economy of the entire fleet of U.S. cars and light trucks declined from 26 mpg to 24 mpg-in part because of the rising proportion of gas-guzzling sport-utility vehicles (SUVs). Yet in March, when auto industry lobbyists claimed that building more fuel-efficient cars would be “too difficult,” the U.S. Senate once again killed legislation that would raise the country’s Corporate Average Fuel Economy standards. It was a familiar dance; Congress has not raised the standards even once during those same 17 years.

It’s not that automotive technologies haven’t improved; it’s that the improvements have been geared toward delivering power, not efficiency. Since 1981 the auto industry has hiked horsepower 84 percent, allowing vehicles to accelerate faster even though they have gotten heavier, according to the U.S. Environmental Protection Agency. “That’s what consumers want,” says Fritz Indra, executive director of advanced engineering for General Motors’ Powertrain division. “Each year Americans want a little more space inside, a little more power.”

But is it really too difficult to build a reasonably priced SUV that can get 40 mpg and still provide the performance, comfort, and reduced emissions consumers expect? The surprising fact is that an assortment of fuel efficiency technologies exist in industry and university labs. Even more startling is that many of these technologies are based on the conventional internal-combustion engine. They don’t require complex electric-gas hybrid drive trains like those under the hoods of the Toyota Prius and Honda Insight (see Visualize). Nor are they based on anything as exotic as fuel cells. If the automotive industry put some corporate horsepower behind moving these technologies into production-and that’s a big if, given the lack of U.S. regulations and consumer demand-the gas-saving technologies could start hitting showrooms within five years. Indeed, if it chose to, Detroit could manufacture a 40-mpg SUV by the end of the decade.

The gains would come largely from emerging technologies such as improved control systems that minimize energy losses in the engine and transmission, as well as efficient electrical components-from water pumps to engine valves-that could replace belt-driven mechanical systems. Existing technologies, such as advanced transmissions and fuel injection systems, could also play key roles if they were adopted more widely.

Indeed, if all new cars and light trucks adopted available and emerging gas-saving technologies, the average fuel economy of U.S. cars would surge to 46 mpg, up from today’s 27 mpg. And SUVs could average 40 mpg, up from today’s 21 mpg, according to a recent study prepared in part by John DeCicco, a senior fellow at Environmental Defense, a New York Citybased environmental group. (The study was coauthored by Feng An, a modeling expert at Argonne National Laboratory, and Marc H. Ross, a physicist and automotive-policy expert at the University of Michigan.) Two-thirds of the benefit would come from improving the power train, and the rest would come from cutting weight and reducing aerodynamic drag and rolling resistance. And even though retail prices of vehicles would rise some $1,000 to $2,000, depending on the model, consumers would save that much at the gas pump within five years. “The industry doesn’t lack the technology, it lacks the priority,” DeCicco says.

Such improvements in gas mileage would have a huge impact on U.S. oil dependence and the environment. According to the Union of Concerned Scientists, if the U.S. fleet’s fuel use improved to 40 mpg, the nation would save two million barrels of oil a day-75 percent of all the oil the United States imports from the Middle East. And it could mean a 30 percent decrease in greenhouse gases, chiefly carbon dioxide.

Automakers-while not debating the essential truth of such numbers-say that reliable, affordable versions of these new components and software controls are harder to implement than it may seem. But the manufacturers, while characteristically tight-lipped about production plans, have created advanced prototypes of these technologies and even installed early units in some vehicles. Because many of these technologies are readily available and based on the internal-combustion engine, they could have tremendous impact in the next several years. “There’s a lot of potential here,” says John Heywood, director of the Sloan Automotive Laboratory at MIT. “It’s our best hope for continuing to reduce emissions and fuel consumption of our ever growing vehicle fleet.”

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