Of all the performance figures we logged with the BMW 6 Series, only one seemed below par. BMW claims 5.0sec dead for the 650i convertible's sprint to 62mph, but our two-way average from zero to 60mph – 5.6sec – suggests that’s a bit optimistic. The six-cylinder 640i shouldn’t be a whole lot slower, as BMW’s claimed 0-62mph time for that car of 5.7sec suggests.
But don’t think that any 6 Series is anything other than seriously rapid. The 640d is the least powerful in the range but even so has more than 300bhp and rides on a 464lb ft swell of torque, so can reach 62mph virtually as quickly as the 640i. All engines, in truth, have plenty of short intermediate gear ratios, wide plateaus of torque and a superbly fast-acting eight-speed auto gearboxes In particular, the 650i can simply hurtle into the middle distance when you want it to; we measured it reaching 100mph in 12.4sec.
Better still is the flexibility of performance. That kind of urge makes overtaking easy almost no matter which gear you’re in, and it allows you to travel every bit as quickly as the terrain permits.
In the M6, this crushing performance is upped even further. Headline outputs of 552bhp and 501lb ft make for a hugely fast car at any revs and in any gear. Select the right options and the M6 is capable of 189mph.
And, if you’re a fan of laid-back ground-covering, there’s no ostentatious exhaust blare that comes along with that performance. There’s a bassy, cultured V8 woofle from the 650i, sure, but certainly not the kind of howl that announces itself from 200 yards or impinges upon cabin refinement at speed.