* Least-expensive car to win green award so far
* Green cars still command only tiny slice of U.S. market
* Judges impressed by range of versions
LOS ANGELES, Nov 29 (Reuters) - Ford Motor Co, which has emphasized boosting the fuel economy of its lineup to attract car buyers, won a top "green car" award for its Fusion midsize sedan, making it the least expensive model yet to earn the title.
In the past, sales of green vehicles have been hampered by their relatively high price tags.
The Fusion, which starts at $21,700 for the gas-powered base model, won because it is offered in a wide range of powertrains, said Ron Cogan, editor of Green Car Journal, which gives out the annual award to recognize leadership in cutting emissions.
"It won by virtue of the fact that it offers an array of choices," Cogan said after announcing the award during the LA Auto Show on Thursday. "This is huge."
The second-largest U.S. automaker offers gas-powered, hybrid and plug-in hybrid models. The Fusion hybrid is estimated to get 47 miles per gallon, although early tests by Consumer Reports magazine signal that the Fusion hybrid, like other hybrids that have been tested, may fall short of that figure.
A hybrid is an automobile with more than one power source, such as an electric motor and internal combustion engine or an electric motor with battery and fuel cells for energy storage.
Ford spokesman Wes Sherwood said the company was expecting to see a wider range for fuel economy on its new generation of hybrids because it is not asking drivers to compromise on vehicle performance.
"If you want to drive for maximum fuel economy, the car has the tools. You can do it," Sherwood said. "If you want to drive 80 miles per hour on the highway you aren't going to get 47 miles per gallon."
All five finalists for the 2013 award are available to the mass market, underscoring the auto industry's ramped-up focus on boosting fuel economy over their entire lineup, not just in low-volume, specialized vehicles.
The finalists included the Dodge Dart Aero, a turbocharged version of Chrysler Group LLC's compact car, and Mazda's CX-5 SkyACTIV crossover, both of which start around $20,000.
The others were Toyota Motor Corp's subcompact hybrid, the Prius c, which starts at $18,950, and the Ford C-Max, which starts at $25,200 for the hybrid model.
"(The LA Auto Show) used to be all about electric vehicles, which really don't suit everyone," said Jake Fisher, Consumer Reports' director of automotive testing. "Now you're seeing fuel economy for everyone."
Previous winners of the Green Car award have included General Motors Co's plug-in Chevrolet Volt, which costs just under $40,000, and Honda Motor Co's natural gas-powered Civic, which starts around $26,300.
The award has been presented since 2006, when Ford won for its Mercury Mariner hybrid, a since-discontinued sport-utility vehicle that got about 27 mpg and had a starting price of nearly $30,000.
The 2013 Fusion's gasoline-powered base model gets 34 mpg on the highway, while the hybrid version gets 47 mpg, according to data from the Environmental Protection Agency. The plug-in Fusion Energi includes 20 miles of all-electric range, with a backup gasoline-electric hybrid powertrain.
Ford has revitalized sales in recent years in part because of a renewed focus on fuel economy and smaller, more efficient cars. Ford has also adopted a more flexible manufacturing strategy that allows it to build gas-powered, hybrid and electric models all on the same assembly line.
The average fuel economy of Ford's cars and trucks for model year 2011 was 21.3 mpg, up from 18 mpg in 2006, U.S. government data shows. The industry average for 2011 was 22.8 mpg.
Early tests by Consumer Reports indicate that the Fusion and C-Max could fall short of EPA's estimates of 47 miles per gallon for both models, Fisher said.
"I'd be surprised if we get near that," Fisher said.
But he added that it was not uncommon for hybrids to fall short of the EPA estimates, citing the Prius as an example.
Official testing by the influential consumer watchdog is just beginning, but in routine driving by researchers, "we haven't seen anything close to 47," Fisher said.
While the industry is shifting focus to improving fuel economy, hybrids like the popular Toyota Prius and the Volt still account for less than 3 percent of U.S. auto sales, said Lonnie Miller, analyst with Polk Automotive.
Sales of electric cars like Nissan's Leaf and the Volt have lagged expectations, despite high gasoline prices, in part because the cost of the batteries that power them is very high and normal internal combustion engines are getting much better mileage per gallon than in the past.
Fisher said that the past couple of years have been characterized by incremental improvements rather than big breakthroughs when it comes fuel economy of new vehicles.
"There's not a whole lot of 'hit 'em right out of the park' vehicles here," he said. "There's no new Tesla being introduced. You look at the Green Cars of the Year. There is nothing really earth-shattering."
The winner was selected by a panel of environmental leaders, including Sierra Club Executive Director Michael Brune, Ocean Futures Society President Jean-Michel Cousteau, Global Green USA President Matt Petersen, television personality and car enthusiast Jay Leno and staff of the Green Car Journal.
Ford shares closed 2.5 percent higher at $11.53 on the New York Stock Exchange on Thursday.