When we road tested the BMW 650i convertible we returned of 28.9mpg on a lengthy run, which may sound thirsty to many, but by the standards of its V8 drop-top peers, many of which struggle to better 25mpg on the run, it is frugal. Emitting 249g/km of CO2, this 6 Series is also £200 cheaper to tax every year than an equivalent Jaguar XK or Mercedes SL500.
Saving around £8000 off the list price and going for the 640i will save you a decent amount at the fuel pumps if the official average figures are anything to go by. The six-cylinder car beats the V8 by 9mpg (35.7mpg versus 26.4mpg), while CO2 drops usefully to 185g/km; that’s a few tax bands, meaning a sizeable company car tax saving of the best part of £300 per month.
Likewise, that might make the 640d and its 51.4mpg combined economy and 144g/km figure even more compelling. Value seems to speak strongly for the car, too. At well over £70,000, the 650i convertible is still cheaper than the entry-level Porsche 911 cabriolet – undercut only by Jaguar’s 5.0-litre XK – and comes with 19in alloy wheels, Dakota leather upholstery and a 10.2in sat-nav system.
Just beware the options list, because a fully loaded 650i with Adaptive Drive, Integral Active Steering, a head-up display and all of the other toys will cost you more than £94k.