This is BMW's dream car of sorts. Oddlly titled the Vision EfficientDynamics, it's a high-performance sedan that's healthy to mimic the efficiency of a subcompact.

And how does BMW think it could accomplish this? By combining a 1.5-liter direct-injection diesel engine and two electric motors. Altogether, the all-wheel drive setup delivers a total of 356-horsepower while still managing to return 63 mpg according to European testing standards.

Or course, like all concepts, the mileage number depends on my factors that haven't been ironed out yet, so take it all with a grain of salt. We're sensing a slight trend here.

2009 Frankfurt Auto Show