DETROIT – With the ink still wet on a congressional mandate to boost fuel economy to 35 mpg (6.7 L/100 km) by 2020, every auto maker at this year’s North American International Auto Show is talking about fuel consumption – even Ferrari SpA.

Today, the Italian icon for exotic sports cars unveils a concept F430 Spider Biofuel designed to run on E85, an alternative fuel made up of 85% ethanol and 15% gasoline.

A growing number of E85 flex-fuel vehicles now are now available in the U.S., particularly fullsize pickups and SUVs.

But the F430 Spider Biofuel is purely a concept, and there are no immediate plans for production, says Amedeo Felisa, Ferrari general manager. The auto maker first showed the concept at a technology conference in June in Maranello, Italy, Ferrari’s hometown.

“We show it in Detroit because there is a natural interest in biofuels,” Felisa tells Ward’s. “If the reaction is positive, then we will be ready with the next model to install the solution.”

Felisa balks at the notion of integrating the biofuel capability into an existing Ferrari vehicle. “If the market is asking for this, we will be ready to do it.”

In preparing the F430 for flex-fuel capability, Ferrari engineers modified the engine controller, while the compression ratio and all other technical characteristics of the modular 4.3L DOHC V-8 remain unchanged.

The alterations are good for an extra 10 hp, a 4% boost in torque and a 5% drop in carbon-dioxide emissions, while maintaining the same curb weight.

Biofuels are not Ferrari’s “final solution” to improving fuel economy in the face of stricter requirements soon to arrive in Europe and the U.S., Felisa says.

He declines to say whether turbocharging, downsized engines or gasoline direct injection factor into Ferrari’s future powertrain strategy, but Felisa admits the auto maker remains a long way from achieving its goal.

Even in the face of strict, new legislation, Ferrari remains boldly confident it will continue selling expensive, high-performance cars in the U.S., well beyond 2020.

“I believe there will always be space for a Ferrari, because no one will have the courage to keep a car like that out of the market,” Maurizio Parlato, president and CEO of Ferrari North America Inc., tells Ward’s.

The U.S. represents Ferrari’s biggest market, making up 30% of global volume. Ferrari finished 2007 with a record 6,400 deliveries, a 14% increase over 2006.

Sales were up in the established markets of the U.S. and Western Europe, but not as significantly as in the developing regions of Eastern Europe, Asia and the Middle East. Ferrari sold 177 cars in China last year.

Brand loyalists had speculated Ferrari would unveil a smaller, less-expensive Ferrari in Detroit, but Felisa smiles and declines to take the bait.

“We always come with a new Ferrari in the future,” he says. “But if you say a small Ferrari, we always say ‘we don’t have in our plan a small Ferrari.’”

And while competitor Porsche AG has withdrawn as an exhibitor at this year’s NAIAS, Felisa says he anticipates Ferrari will be back again in 2009.

“The U.S. is our major market,” he says. “I think it’s important for us to be present in Detroit.”