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

Nissan Qashqai

Nissan Qashqai

RRP £27,415Avg. savings £7,528 off RRP*Used from £11,276
MG MG4

MG MG4

RRP £27,005Avg. savings £6,825 off RRP*Used from £9,749
Nissan Juke

Nissan Juke

RRP £19,785Avg. savings £6,556 off RRP*Used from £9,623
Toyota Yaris Cross
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Peugeot is building a brand new petrol engine – who says ICE is dead?
New Peugeot ‘Turbo 100’ engine

Peugeot is building a brand new petrol engine – who says ICE is dead?

New 1.2-litre three-cylinder petrol engine to replace Puretech motors in Peugeot and more
News
16 Mar 2026
New Rivian R2 details revealed: UK specs, range and pricing for Tesla Model Y rival
Rivian R2 - front tracking

New Rivian R2 details revealed: UK specs, range and pricing for Tesla Model Y rival

The cutting-edge electric family SUV is coming to the UK – but in 2028 at the earliest
News
16 Mar 2026
Jaecoo 7 range boosted by new hybrid SHS-S and flagship Black Luxury models
Jaecoo 7 SHS-S - front

Jaecoo 7 range boosted by new hybrid SHS-S and flagship Black Luxury models

The popular Jaecoo 7 range adds a new hybrid model to slot between the petrol and plug-in variants
News
18 Mar 2026