From £29,7006
Fitted with the mid-range engine, Munich's 4-series cabrio lacks top-down stateliness, which is hard to forgive in a car built for stylish cruising

What is it?

It’s the BMW 4-series family’s drop-top in 428i auto spec, meaning it’s powered by a 242bhp turbocharged 2.0-litre four-pot sending power to the rear wheels via an eight-speed automatic transmission.

This is the 4-series convertible’s mid-range engine, bookended by the 420d’s 181bhp 2.0-litre turbodiesel and the 435i’s 302bhp turbocharged straight six, both of which we’ve already sampled.

The 4-series convertible picks up the baton from the E93 3-series drop-top, gaining 26mm in length and 50mm in wheelbase, while added track width and a 10mm drop in ride height also help it assume a more planted and athletic stance.

The 4-series coupé’s svelte lines aren’t quite recreated in the convertible, though: the three-piece folding hard-top dictating a more angular trailing roofline than that of its fixed-head brother.

Torsional rigidity is 40 per cent higher than in the E93 (which also used a folding hard top), although the new model is claimed to be up to 20kg lighter. That said, our car’s 1775kg kerb weight is a staggering 230kg more than its coupé counterpart’s, and 115kg more than that of the equivalent Audi A5 cabriolet, which uses a lighter fabric roof. 

Even with the roof up, a considerable 53.4 per cent of the 428i’s mass lies over the rear axle (it’s 54 per cent in the manual version), but BMW has reconfigured and strengthened the rear suspension in a bid to counteract the dynamic implications of this sumo-on-a-see-saw weight distribution.

Entry-level SE spec is generous, with highlights including parking sensors fore and aft, leather upholstery, heated front seats (electrified as standard in the convertible to aid rear-seat access), colour 6.5in screen and Drive Performance Control (DPC) to toggle dynamic settings. 

Our car’s Luxury spec adds £2500 to the SE’s £38,570 price tag and brings the likes of 18in alloys, sports seats, sat-nav and smatterings of chrome and wood.

What's it like?

The cabin is mainly carried over from the 3-series, so is smart and effective rather than beautiful, but the driver’s seating position and ergonomics are sound.


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In the two rear seats, legroom is still tight despite the wheelbase gain, the seatbacks are conspicuously upright and headroom is cosy for taller occupants with the roof up – not especially hospitable for adults, then.

The boot swallows just 220 awkwardly distributed litres when the roof is stowed and you gain just 150 litres when it isn’t, but that’s only 10 less than in the Audi A5 cabrio.

The roof itself takes 20 seconds to fold up or down, and can be moved at up to 8mph; the A5’s is a couple of seconds quicker and operates when travelling at up to 30mph. The car wobbles a bit as the complex mechanism whirrs away, too.

With the roof up, the cabin feels impressively cocooned, and although you can’t hear much from the engine as it smoothly gathers momentum from 2500rpm, you can feel it fighting the convertible’s extra mass. 

Drop the roof and things change – in town, there’s a bassy drone from the exhaust, mixed in with whooshes from the turbo and upshift ‘whumps’ under throttle, none of which is especially dignified or relaxing in an open-top tourer.

Motorway refinement is good, though: with the £265 wind deflector in place, you can chat away comfortably at 70mph. The eight-speed auto ’box is as slick as ever, blurring upshifts with DPC in Comfort mode and flashing through them in Sport.

Putting our car’s slightly neurotic Variable Sport Steering (an unnecessary £250 option) to one side, the 428i can’t mask its uneven weight distribution, or its lack of top-down rigidity.

Roll is relatively well contained, but the car isn’t comfortable taking corners at pace, feeling significantly less tied-down than its fixed-head brother, and rippled Cotswolds roads elicited pronounced pattering from the suspension, much of which resonated through the steering column.

Should I buy one?

You can understand the 428i convertible’s shortage of dynamic edge, but its lack of top-down stateliness – both in terms of powertrain refinement and ride quality on our weathered roads – is less easy to swallow. 

In terms of the engine, an entry-level 420i option, using the calmer 181bhp version of the same unit, might have been more in line with the car’s relaxed remit.

As it is, the 420d is slightly cheaper and more economical, but also suffers refinement ills, which leaves the pricey but smooth-running and rapid 435i as the 4-series convertible’s engine of choice.

Depending on trim choice, the A5 cabrio in front-drive 222bhp 2.0 TFSI Multitronic form – which is slightly slower but lighter and cleaner than the 428i auto – costs at least £1600 less. Despite the BMW’s added modernity and sophistication over the Audi, it’s hard to argue that its premium is worthwhile.

BMW 428i Luxury Convertible

Price £41,070; 0-62mph 6.4sec; Top speed 147mph; Economy 42.8mpg; CO2 154g/km; Kerb weight 1775kg; Engine 4 cyls, 1997cc, turbo, petrol; Power 242bhp at 5000-6500rpm; Torque 258lb ft at 1250-4800rpm; Gearbox 8-spd automatic

Join the debate


26 June 2014
BMW used to be the absolute pinnacle of driving prowess but one model after another are leaving even German-loving motoring journalists underwhelmed!

27 June 2014
Why £41,070 to hear that souless engine???

Where is BMW?

27 June 2014
Dark Isle has asked a very good question. The article actually has some of the answers. The choice to do away with straight sixes and use turbo 4s is the wrong one. The refinement of the N20 engine (420i and 428i) is, for the money being charged by BMW, appaliing. I had several long test drives of this engine in both states of tune (320i Sport and 328i Luxury) to try to decide if I should replace BMW Number 10 (E92 330i M Sport Coupe) with the new 4 Series or 3 Series. After a few days driving the N20 the answer is NO. The petrol N20 engine sounds like a diesel on start up and the underlying harshness of a 4 cylinder never goes away even after 100+ miles. The noise it makes is uncouth under load and anodyne when cruising. The fuel economy benefits are non-existent on one journey in the 328i it averaged 0.1 mpg better than my 330i. To buy a 428i with the same kit as my present car would cost £45500 (when my 330i was new it cost £41900, the new car is £2600 more expensive for less bhp (242 vs 272). Even opting for a 328i would cost £40000+. Given the essentially unremarkable nature of the N20 engine these sorts of prices are ridiculous. A 4 cylinder BMW like this ought to be badged as a 418Ti and priced accordingly. BMW no longer sells a petrol six cylinder car without a turbo for less than £40K that has running costs as reasonable as my 330i. As a private buyer spending my own money I do not care about Benefit in Kind or emissions. My car averages 27 mpg around town and can easily do 40mpg on a long journey. It costs me £200 a year to tax and £350 to insure. It sounds fantastic whether being revved or just cruising along. I was asked to consider a 335i/435i by my dealer but I was quoted a minimum of £1200 a year to insure the 335i or £1400 to insure the 435i. I drove a 335i anyway to see if it might be worth it but fuel ecomony on a 30 mile test drive was 22mpg but dipped to 18mpg when I used the power. As the price of a 435i with the same kit as my 330i was £54000 I realised I could get a used Porsche Cayman and buy a Ford Focus as practical car for that sort of money.

BMW's quality has also been declining as far as interiors and paintwork is concerned for several years and their products are now becoming overpriced. BMW are trying the same strategy that Mercedes-Benz tried in the 1990s - filling every niche and expanding the range. Not necessariliy a bad thing if done correctly. For Mercedes-Benz and now for BMW this is leading to a lowering of quality across the range and a cheapening of the engineering content of their cars. Having just returned from holiday where I drove a Kia Optima hire car (with a petrol engine) I am now of the view that BMW is trading on the badge alone as the Kia was quieter, more comfortable and better made than the 320i and 328i. It also sounded nicer than the N20 engine. The badge engineering strategy is OK for Audi which can be subsidised by the rest of VAG so they do not have to develop drivetrains or chassis and just concentrate on interiors. BMW have no parent company subsidising them. As soon as the public realises that BMWs are now just 4 cylinder repmobiles with a badge and the fleet managers find something cheaper they will go and buy elsewhere. Loyal BMW owners like me who bought the cars for the straight six engines and the engineering will have gone elsewhere, as I will be doing, particularly as the Front Wheel Drive BMW is only weeks away. Why pay £40K and upwards for a car with a 2 litre turbo that is not particularly well made? VW will sell me a FWD Golf GTi or (Passat) CC with not dissimilar performance to a 328i/428i and decidedly superior performance to a 320i/420i for £12K less.Jaguar may sell an XKE for less as well. Lexus and Infiniti are waiting in the wings and of course so is Audi if a badge is important. This may the beginning of the end for BMW.

28 June 2014
BMW completely lost it. They think cluttered styling makes for charismatic design. The last relatively great designs were the previous 3 series (before the major touch up), particularly the touring and the M version, and the Z4 coupe.

29 June 2014
Six cylinders good, four cylinders bad? Try three! I've heard no complaints about harshness in the Mini and I8 threes.

30 June 2014
Fitting BMW's new 1.5 3 cylinder petrol turbo engine to the 3/4 Series might be a good idea. It is certainly capable of producing as much power as the N20 petrol engine currently used in the 3/4 Series as evidenced by its use in the i8. From all accounts it is a zesty and charismatic engine just like BMW engines used to be. It may even be better on fuel consumption. As stated in my long post above having driven 2 variants of the N20 neither is as economical as BMW claims and in fact no more economical than the 3 litre straight six in the E92. The only reason BMW have switched to this travesty of an engine is cost (it is much cheaper to engineer resulting in more profit for BMW) and EU emissions (which wrongly place CO2 as the be all and end all). On another note, as voyager12 says BMW's current design language is terrible. I own an E92 330i Coupe which remains almost crease and clutter free in design and is elegant and restrained. The new 3/4 Series cars have at least 7 different "character lines" or creases at the front end. This is particularly noticeable at the junction of the A pillar and the bonnet. Far too fussy and inelegant. When I pointed this out to the salesman he said it was all because of crash regulations and pedestrian impact rules. If one looks at the new Ford Mustang it is clear designers can make a car striking and iconic without silly folds and creases everywhere. The F-Type Jaguar also shows how to design an elegant modern car that complies with all the necessary legislation. BMW has definitely lost it's mojo.

1 August 2014
I have to say the only bmw I would personally consider is a M135i - its not the prettiest car in the world - but for me is ideal and not far off a golf when you add the perfomance pack. I need 5 doors so can't have a M235i.

I do agree with other posters - to me a BMW is suppose to be a drivers car, with the lower cars becoming fwd drive car enthusiasts will go elsewhere. I know a lot of people don't really care about the car they have - but some of us still do. I may only drive a astra diesel at present but my financial situation is now changing and I would like to experiance a straight 6 engine before they do completely die of extinction.

I would also like a v8 but will have to wait till I visit america to experiance one.

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