Joseph Lucht, left, and Ronald Drummeller look over the new Volkswagen XL1 car during the Society of Environmental Journalists Conference at the Chattanooga Convention Center on Friday. The car, which VW claims is the most fuel-efficient and aerodynamic production car in the world, will be sold in Europe and could be modified for the American market.

Chattanooga was the site Friday for Volkswagen's U.S. debut of a super-lightweight production car the automaker calls the world's most fuel-efficient and aerodynamic.

The two-seater, dubbed the XL1, can go more than 200 miles on a gallon of diesel fuel, according to VW.

"A year ago it was a concept car. Now it's a production car," said Volkswagen Group of America spokesman Carsten Krebs.

The two-door car is powered by a plug-in hybrid drive system featuring a two-cylinder TDI engine, a 27-horsepower electric motor, a lithium-ion battery and a seven-speed dual-clutch automatic transmission.

But VW engineers said that's just the start of what makes a fuel miser out of the car, which was unveiled before the Society of Environmental Journalists meeting in the city.

"It's a combination of technologies," said Oliver Schmidt, general manager of Volkswagen Group of America's engineering and environmental office.

It's made with carbon fiber in places and comes in at just 1,753 pounds, the company said. That's about 1,000 pounds less than a 2013 two-door VW Golf, for example.

The XL1 also has a sports-car design and low center of gravity to boost its aerodynamics. It's 153.1 inches long and only 65.6 inches wide, just enough to squeeze in a pair of body-shaping seats. In addition, the car is a measly 45.4 inches tall. By comparison, a Porsche Boxster is 5.1 inches taller, according to VW.

The car offers four "low-rolling tires," said Schmidt, which help boost fuel efficiency, and gull-wing doors.

People look over the new Volkswagen XL1 car during the Society of Environmental Journalist Conference at the Chattanooga Convention Center.

Conceptually, the XL1 is in a third evolutionary stage. Dr. Ferdinand Piech, now chairman of the VW supervisory board, had a goal nearly 15 years ago of producing a practical car with ultrahigh fuel mileage.

In the versions of the car shown in 2002 and 2009, the driver and passenger sat in a tandem arrangement for optimal aerodynamics. In the car shown Friday, the two occupants sit slightly offset, side by side, almost like a conventional vehicle.

Christoph Benke, a development engineer in the company's Wolfsburg, Germany, headquarters, said the car has interior camera monitors rather than exterior side mirrors, for reduced drag.

He said VW is the only auto manufacturer with a street license for the camera innovation.

Benke said the car, made at a plant in Osnabruck, Germany, is expected to go on sale in Europe next year. He said there's no timetable for sales in the U.S.

The price tag wasn't revealed.

Krebs said 50 have been produced so far, and plans are to initially make about 250.

Contact Mike Pare at mpare@timesfreepress.com or 423-757-6318.