Obviously the xDrive is safest because it it has four-wheel drive, but that will take the edge off the economy of a 320d. I averaged 63mpg over 8000 miles in a 320dED over a winter, which is the best I've ever done in any car.

The Mazda 6 2.2 Skyactiv 150 is very good to drive, 'feels' safer than a rear-drive 3 Series and averages 51 Real MPG. The Octavia is a decent. solid feeling car, best bought as an estate, and averages 54.2 Real mpg.