On one stage of the Los Angeles Auto Show, BMW shows off "the cars of tomorrow," concepts powered by electricity. On another, Audi touts four new diesels. Ford, meanwhile, displays a tiny gasoline motor with an unprecedented mix of power and economy.
With consumers and the government demanding ever-higher fuel economy, automakers are tripping over one another at this year's auto show to trumpet technologies that squeeze more miles out of a fuel tank or an electric charge.
Until recently, peak fuel efficiency demanded a trade-off in performance and comfort. But the increasingly varied entrants in the miles-per-gallon race now offer substantial power and comfort.
"Instead of having a couple of electric vehicles, which are really only suited for a few people, you have mainstream vehicles that get you what you want and have the fuel efficiency you need," said Jake Fisher, automotive test director for Consumer Reports.
With gasoline prices above $3.50 a gallon in much of the nation, auto companies now market themselves more on fuel economy than horsepower, but their engineers are getting better at combining healthy doses of both.
Fuel economy has taken on greater importance with President Barack Obama's re-election, which automakers believe will cement federal regulations that require nearly doubling the average gas mileage for passenger vehicles to 54.5 mpg by 2025. If there's a lesson about fuel economy emanating from the auto show, it's that there are many roads to the new fuel economy standards.
"I hope the horse race continues," Fisher said. "I hope that automakers keep trying different things. And it might be that the eventual dominant technology is not even something that we have thought of."
At the L.A. Auto Show, which runs through this week, Audi showed off a line of vehicles equipped with turbocharged V-6 diesel engines that are expected to achieve as much as 30 percent better fuel efficiency than the gasoline counterparts the German automaker now sells.
Ford unveiled a gas-sipping, turbocharged, three-cylinder engine that packs more punch than the base four-cylinder now standard in its small cars. Depending on fuel economy tests, the Fiesta equipped with this engine may become the first non-hybrid gasoline vehicle to meet the 2025 gas mileage standards.
Chevrolet introduced the electric version of its Spark that it will bring to market next year, hoping to attract customers with an electric car priced at less than $25,000, after a $7,500 federal tax credit.
Some of the cars on display, including the Ford Fusion hybrid, the Toyota Camry hybrid and the Lexus ES 350 hybrid, already meet the 2025 standards. The 54.5 mpg standard is based on a technical regulatory formula; in real-life driving, it's expected to translate to 37 mpg to 40 mpg.
That compares to the average fuel economy of 24.1 mpg for new vehicles purchased in October, a 20 percent jump from the same month in 2007, according to the University of Michigan Transportation Research Institute.
"You are seeing the suite of technologies in different vehicles to improve fuel economy," said Don Anair, the automotive analyst at the Union of Concerned Scientists.
The technologies go well beyond engine types. They include eight- to 10-speed transmissions; improved aerodynamic body shapes; lighter-weight body panels and chassis components; tires with lower rolling resistance; start-stop systems that shut off the engine at red lights; and turbocharging, which creates a denser air-fuel mixture in the engine's cylinders.
More exotic technologies, such as pure electric engines or hydrogen fuel cells, probably won't be sold in numbers large enough to meet more stringent fuel economy targets.
"The heavy lifting will be done by conventional gasoline technology and hybrids," Anair said.
Beyond engines, automakers are aggressively looking to save weight, a huge factor in fuel economy. Nissan has the newest generation of its Pathfinder sport utility vehicle front and center at its display. The vehicle is bigger -- more than 4 inches wider and longer -- and has more interior volume, yet gets about 30 percent better fuel economy. The new Pathfinder is 500 pounds lighter than the vehicle it replaced.
Nissan has trimmed more than 100 pounds from the body, more than 35 pounds from the seats and interior trim and even nearly 16 pounds out of the radio and navigation components. It also achieved a 13 percent improvement in aerodynamics with sleeker styling.