From BMW press release:

• High-performance concept study with BMW ActiveHybrid technology
visualising the dynamic performance typical of a BMW against the backdrop of future demands in sustained mobility. BMW Vision EfficientDynamics as a symbol for the future of Sheer Driving Pleasure in harmony with trendsetting efficiency.
• Development aim: The performance of a BMW M Car and a highly emotional character combined with the fuel economy and emission management of a modern small car in the premium class. As a result, this unique sports car offers the most consistent rendition of the BMW EfficientDynamics development strategy.
• Innovative approach in the context of BMW EfficientDynamics: The exceedingly good balance of CO2 emission management and driving pleasure results from a revolutionary vehicle concept developed all in one from the ground up, achieving a new level of efficiency combined with a unique driving experience. The overall result goes far beyond the sum total of the individual features and components in this concept car.
• BMW Vision EfficientDynamics offers a realistic impression of the unique potential of BMW ActiveHybrid technology and the great innovative thrust of BMW EfficientDynamics.

Technology:

• Offering a full-hybrid concept, the BMW Vision EfficientDynamics concept car is powered by a three-cylinder turbodiesel and two electric motors. Overall system output is 262 kW/356 hp, maximum torque 800 Newton-metres/590 lb-ft. All-wheel drive featuring an electric motor on both the front and rear axle.
• Anticipated performance: Acceleration from a standstill to 100 km/h in 4.8 seconds, top speed 250 km/h (155 mph) (electronically limited) , fuel consumption in the EU test cycle 3.76 litres/100 km (equal to 75.1 mph imp), CO2 emissions 99 grams/kilometre.
• As a plug-in hybrid, BMW Vision EfficientDynamics is able to cover the entire fuel consumption drive cycle under electric power alone. Taking the sources of energy used for generating the electric power consumed into account (EU electricity mix), this reduces the CO2 emission rating to just 50 grams per kilometre.
• Electric power is generated without the slightest increase in fuel consumption through a particularly efficient concept of Brake Energy Regeneration. Energy is stored in 98 lithium polymer cells. The car is able to cover a distance of approximately 50 km/31 miles in the electric mode alone.
• Aerodynamics developed with know-how from Formula 1. CX drag coefficient optimised to just 0.22. Forward-looking energy management uses the maximum potential available in each case to minimise fuel consumption.

Design:

• Technology-oriented body design as a clear expression of consistent lightweight technology and aerodynamic quality. Design language typical of the brand, setting clear signals in terms of sporting performance and optimum efficiency.
• The 2+2-seater concept combines dynamic performance and supreme efficiency with an enhanced level of all-round function. BMW Vision EfficientDynamics symbolises BMW’s commitment to offer an unprecedented driving experience for up to four occupants.
• BMW Vision EfficientDynamics comes with gullwing doors opening up to the side. Innovative, weight-optimised door kinematics makes entering the car at both front and rear convenient and very easy.
• The interior of this unique 2+2-seater intentionally demonstrates the very latest in modern technology. At the same time the use of natural materials underlines BMW’s strategy of sustainability borne out through this concept car.
• The roof and door inserts made of polycarbonate glass automatically become darker as a function of incoming light.