It doesn’t matter which engine you choose for the 6 Series, performance will be at the very worst rapid. Kicking off the range are a pair of turbocharged six-cylinder models, a diesel badged 640d or a petrol that wears the 640i nametag. Although the petrol is a bit more powerful, both can manage 0-62mph in 5.3sec before running on to an electronically limited 155mph top speed.
Next up is the 650i with its twin turbocharged 4.4-litre V8. This 444bhp lump cuts the 0-62mph time to just 4.6sec. If that isn’t enough, the M6 has a more heavily worked over version of the V8 with either 552bhp or 592bhp if you opt for the Competition pack. The ‘regular’ M6 scorches to 62mph in 4.2sec with the Competition managing a stunning 3.9sec.
The 640s and 650 come as standard with BMW’s eight-speed automatic gearbox that smoothly shifts between ratios. M6s get a racier seven-speed ‘box that isn’t as smooth, but is much more responsive in manual mode.
Although the M6’s thumping performance might appeal, it’s worth remembering that no 6 Series is what you’d call a sports car. There’s certainly plenty of grip and you can cover ground very quickly, but you’re always aware of the car’s hefty weight and slightly numb steering.
No, we’d advise sticking to the 640d as it’s more than quick enough, is very refined and will prove the cheapest to run by far. Our experience also suggests opting for the Variable Damper Control (VDC) will give the most comfortable ride as will the 18in wheels of SE spec cars. Bigger wheels not only make the ride harsher, they also make road noise noticeably louder. With that in mind, we’d avoid M Sport trim.
Whichever combination you go for, the 6 Series is at its best cruising at speed. With VDC set to Comfort+ it’ll waft along motorways and A roads with ease. Slow down and you do notice urban ruts cause some disturbance, but the suspension rarely crashes.