BMW to build plug-in hybrid sports coupe

BMW has thrown its hat into the eco-supercar ring by confirming plans to place the Vision EfficientDynamics concept into production.

The futuristically styled plug-in hybrid was first revealed at the Frankfurt motor show in 2009. It is set to undergo an accelerated development program that aims to place the low-slung four-seater on sale in all of BMW's key world markets, including North America, by October 2013.

With performance targets similar to the M3--0 to 62 mph in 4.8 seconds and a top speed limited to 155 mph--the new carbon-fiber-bodied coupe won't be BMW's fastest production model. That accolade will go to next year's redesigned M5 with a twin-turbocharged 4.8-liter V8, according to Munich sources.

But with combined city/highway fuel economy of more than 63 mpg (U.S.) and a CO2 emission rating of just 159 grams per mile, it will be among the company's most frugal production cars.

Speaking at a media presentation in Leipzig, Germany, on Thursday to commemorate the start of the Vision EfficientDynamics development process, BMW R&D chief Klaus Draeger said: "This car will crown our lineup. In terms of technology, it sits well above anything we currently offer."

BMW has carried out more than 37,000 miles of testing with the car's diesel-electric powertrain. However, program officials suggest the as-yet-unnamed two-door will undergo significant changes before reaching production.

The first running prototype remains true to the concept car by using a combination of diesel and electric power. At the heart of the testing mule is a 1.5-liter three-cylinder diesel engine producing 161 hp. Code-named N37, it is the same unit earmarked for BMW's future front-wheel-drive 115d due to debut in Europe in 2014.

The aluminum engine acts as a generator in range-extender mode and can provide direct drive to the rear wheels via a six-speed dual-clutch gearbox. The powertrain also includes two brushless electric motors--a 110-hp unit driving the front wheels and a 52-hp unit mounted next to the diesel engine that powers the rear wheels.

All three power sources can operate independently or, for maximum performance, in combination to generate a total of 323 hp to propel the 3,300-pound car. The drivetrain acts in front-drive, rear-drive or all-wheel-drive modes.

Draeger hints that the three-cylinder diesel engine could be replaced by a more-powerful gasoline engine to make the car more attractive to North American and Asian buyers. Speaking exclusively to AutoWeek, he ruled out the possibility of the Vision EfficientDynamics using a conventional engine without hybrid capability, in the process nixing rumors of a possible resurrection of the legendary M1 running a turbocharged version of BMW's classic 3.0-liter inline six-cylinder.

Set to challenge the upcoming Audi E-tron, the Mercedes-Benz SLS E-Drive and the Porsche 918 RS Spyder, the Vision EfficientDynamics is planned to head an extended range of advanced alternative-drive models being conceived under BMW's secretive Project I effort, which is also developing the all-electric Mega City Vehicle.

BMW says the production Vision EfficientDynamics car will be sold to customers rather than the lease-only strategy being used with the upcoming 1-series ActiveE. Pricing is yet to be set, but Draeger hints that the car will cost more than the current 760Li.

"Technology doesn't come cheap, and this car is packed with everything we know about alternative drive systems," he says.

By Greg Kable