Which used BMW 6 Series sports should I buy?
The sole diesel, the 640d, is a turbocharged 3.0-litre straight six that cranks out 308bhp. It has plenty of low-end shove to make for relaxed cruising and enough power to feel genuinely quick. Refined manners and reasonable running costs make it the sensible choice.
The 640i turbocharged petrol straight six has a little more power than the 640d but needs revving harder to get the best out of it, while with two turbochargers bolstering a 4.4-litre V8, the 650i is significantly faster than the 640 models but much more expensive to buy and run.