Skip advert
Advertisement

BMW 640i Convertible

Turbo 3.0-litre gives cabrio added appeal.

Find your BMW 6 Series
Compare deals from trusted partners on this car and previous models.
Or are you looking to sell your car?
Value my car
Fast, no-nonsense car selling
Value my car

In every respect, the all-new 6-Series Convertible is a great improvement. It’s bigger, faster, more efficient, better built and arguably better looking, plus has a longer equipment list. Apart from the cramped rear seats, there’s little to criticise. There are plenty of gadgets available, and when you take into account its performance and efficiency claims, it makes a lot of sense. Plus, until the diesel arrives, this 640i is the best all-rounder in the line-up.

Advertisement - Article continues below

It’s always tempting to go for the flagship model when choosing a high-performance car. But what if you look further down the range? We’ve already driven BMW’s new 6-Series Convertible in 401bhp 4.4-litre V8 650i trim – so now we see how the 640i stacks up.

Its turbocharged 3.0-litre straight six-cylinder engine offers 320bhp and 450Nm of torque from only 1,300rpm. And that means strong performance. The benchmark 0-62mph sprint takes 5.7 seconds – seven-tenths down on the 650i – while top speed is electronically limited to 155mph. 

Under full throttle, there’s a distinctive straight-six howl, and the unit provides deep reserves of punch for overtaking. But the whole experience is smooth and refined, thanks in part to the superb eight-speed auto box.

It costs around £8,000 less, and is also cheaper to run. The 640i features EfficientDynamics technology, with stop-start and active aerodynamics helping it return 35.8mpg combined and emit 185g/km of CO2. In contrast, the 650i posts 26.4mpg and 249g/km. Adaptive dampers and four-wheel steering ensure it feels much more nimble than a car of this size should. And while the ride is firm, it remains compliant, even on 19-inch alloys. The electrically operated fabric roof folds in 19 seconds (or rises into place in 24 seconds) – a process that can be carried out at up to 25mph.

Plus, refinement is good top up or down, especially with the optional wind deflector. 

Inside, the dashboard remains angled towards the driver and many of the car’s functions are controlled via the iDrive dial. The seats provide a wide range of adjustment and owners can choose from an array of options, including a full-colour head-up display system for the first time. 

The rear seats are suitable only for children, and the boot could have a wider and more practical opening. However,it’s a desirable machine, and the best in the range so far.

Skip advert
Advertisement

New & used car deals

Volkswagen Golf

Volkswagen Golf

RRP £25,235Avg. savings £2,502 off RRP*Used from £11,800
Renault Clio

Renault Clio

RRP £16,160Avg. savings £2,417 off RRP*Used from £7,195
Nissan Juke

Nissan Juke

RRP £19,785Avg. savings £4,644 off RRP*Used from £9,295
Skoda Kodiaq

Skoda Kodiaq

RRP £39,025Avg. savings £3,517 off RRP*Used from £12,481
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

New XPeng X9 seven-seater ‘starship’ will beam down to the UK this summer
XPeng X9 - front static

New XPeng X9 seven-seater ‘starship’ will beam down to the UK this summer

Chinese brand’s “starship of tomorrow” has rear-wheel steering, adaptive air-suspension and some of the fastest charging speeds of any EV around
News
30 Jan 2026
Dacia Bigster vs Citroen C5 Aircross: low prices and plenty of space, but which SUV does it best?
Dacia Bigster vs Citroen C5 Aircross - front tracking

Dacia Bigster vs Citroen C5 Aircross: low prices and plenty of space, but which SUV does it best?

Citroen’s latest C5 Aircross hybrid is aiming to woo budget family SUV buyers, but standing in its way is the wallet-friendly Dacia Bigster hybrid
Car group tests
31 Jan 2026
Big discount on Hyundai Kona Electric as it's green-lit for Government EV grant
Hyundai Kona Electric - front corner tracking

Big discount on Hyundai Kona Electric as it's green-lit for Government EV grant

South Korean brand’s popular electric SUV now starts from £33,500 for the entry-level Advance model
News
30 Jan 2026