What is it?
An executive saloon with a supermini’s CO2 emissions is something unusual, and the 520d Efficient Dynamics’ tax-saving ways will shortly make it the best-selling 5-series.
Like the smaller 320d ED, its frugality does not force a performance compromise. So it’ll do 144mph and, more usefully, hit 62mph in 8.2sec. You can only have the 520d ED as a manual saloon and without the M Sport upgrades favoured by many, but these sacrifices are small for the gains made.
What's it like?
BMW has won the gains with taller gearing, an active radiator cooling flap, stop-start, an intelligent alternator and more streamlined wheels. More subtly, the engine has a special centrifugal pendulum vibration absorber, which allows it to pull improbably low revs in high gears without provoking a grumbling vibro-massage through seat, pedals and gearlever.
It works, too, in tandem with a new Eco-Pro drive mode that encourages fuel-saving gearchanges into sixth from as little as 1500rpm. This mode is accessed via what BMW grandly describes as a Driving Experience Control switch, whose simultaneous adjustments of throttle response, ESP settings, steering resistance and automatic transmission shiftings produce Comfort, Sport, Sport+ and the aforementioned fuel-saving mode, which alters the functionality of the air conditioning and assorted electrical items to lower their energy demands.