The Geneva Motor Show (March 4-16) will mark the world premiere of the BMW Vision EfficientDynamics, a concept car designed to showcase the future direction of the German carmaker's performance-enhancing and emissions lowering innovations. Mild ActiveHybrid tech is combined with a twin-turbocharged four-cylinder diesel engine, a new eight-speed automatic gearbox and even roof-mounted solar panels, and all shrouded in a BMW X5 body.

All these technologies combine to deliver the best fuel economy and lowest emissions of any large 4x4 currently on sale.

The mild hybrid solution uses a compact generator that, for the first time, is flange mounted directly onto the gearbox. This motor produces up to 20hp of on-demand power.

In addition, BMW’s Brake Energy Regeneration is used to efficiently capture energy that would previously have been lost when the engine is on overrun. Innovatively, the alternator is also integrated into the crankcase rather than conventionally driven from the front of the engine.

BMW’s concept uses highly efficient lithium-ion batteries in the boot area to store the power generated. These high-storage-capacity batteries enable optimum use of Brake Energy Regeneration and also create possibilities to power the air conditioning, electric coolant pump and the electric power steering system.