Like the 3 Series, the latest 5 is available in super-frugal Efficient Dynamics form. However, you can't have an automatic gearbox with this model, so we prefer the regular 520d.
With the auto 'box, it sits just one company car tax band above the ED and still averages more than 60mpg. What's more, its 2.0-litre diesel engine is so smooth and strong you won't ever wish you'd gone for one of the bigger, six-cylinder ones.
The 5 Series' refinement is just as impressive in other areas, too. The car is better than all of its rivals at shutting out wind and road noise, which makes it incredibly relaxing for covering long distances in. The seats are superbly cosseting and the high quality of the cabin materials adds to the overall impression that you're always travelling first class.
Our one caveat is that it's essential to specify the optional £985 Variable Damper Control system if you really want your 5 Series to ride and handle as a BMW should. It transforms the car's character and is an absolute must.