BMW 4 Series Convertible (2014 – 2020) Review

The first-generation BMW 4 Series Convertible lasted from 2013 until 2020, offering handsome looks and a folding hard-top roof. This makes it unusual in the cabriolet marketplace, with most rivals using folding fabric hoods. Extra security and improved noise refinement are the main benefits of the metal roof. A hard-top does mean more weight, however, and also eats into the boot space of the 4 Series. Thankfully, the smooth ride and powerful engines help you overlook these issues. A quality leather-lined interior, packed with lots of impressive technology, also helps seal the deal.

Premium convertibles are often at the forefront of motoring fashion, but the BMW 4 Series Convertible seems a little behind the times. Car manufacturers went through a phase of making cabriolets with folding metal roofs, but trends have since moved on. That leaves the 4 Series out by itself, flying the flag for hard-top convertibles. 

Using a metal roof does come with obvious benefits. Security is vastly improved over a fabric soft-top, for starters, while it also does a better job of keeping external noises from entering the cabin. Chilly winter mornings will also be a touch warmer with a metal roof in place, too. 

Although styling may be subjective, to our eyes, the metal roof of the 4 Series Convertible looks better than a fabric roof in a contrasting colour.

It makes the topless BMW appear virtually identical to the regular 4 Series Coupe when the roof is raised. Drop the top and it looks primed for cruising a seafront boulevard with style. 

There are downsides to a complicated folding roof, though. Metal and glass weigh far more than fabric, and then comes to the issue of where to store all the pieces. BMW has effectively had to steal boot space in the 4 Series to hide the roof when lowered, so luggage capacity suffers. Keep the roof up and the boot volume is 370 litres, but lowering it sees this drop to a meagre 225 litres. You will learn to pack light.

The compromises continue into the cabin, with the two rear seats being cramped for adult-sized passengers.

Fitting the optional wind deflector renders the back seats completely useless. It does at least do an excellent job at keeping the cabin free from draughts when driving with the roof down. Those in the front will feel comfortable, with plenty of space and comfort from the electrically adjustable seats.

The level of standard equipment is generous across the range, regardless of the trim level chosen. Leather upholstery is used on all models, while LED headlights, climate control and satellite navigation are all included. The interior itself is fitted with high-quality materials, although isn’t exciting in terms of design. 

Taking on the weight penalty of the roof are a range of engines. The 4 Series comes with a choice of three petrols or three diesels, each capable of making this convertible feel relatively quick. A six-speed manual gearbox is standard on the entry-level 420i, with an eight-speed automatic offered across the range. Given the choice, we go for the smooth-shifting auto.

Although not quite as sporty as the related 4 Series Coupe, the open-top model has the benefit of a smoother ride quality. The steering is light and precise, meaning the 4 Series Convertible feels just as settled on the motorway or city streets. It can also offer some entertainment on your favourite country roads, but the weight penalty of the metal roof sways the 4 Series towards being a cruiser, not a bruiser. 

Turning the 4 Series Coupe into a Convertible saw BMW add more than 200kg in weight. This included extra chassis strengthening, to ensure the open-top 4 Series could still deliver the driving experience expected of a BMW.

Although the extra weight may blunt performance slightly, it means there are no shakes and shimmies with the roof down. It makes the 4 Series Convertible feel taut and composed, with the accurate steering allowing it to be placed on the road precisely. A 4 Series Coupe offers slightly more fun, but a roofless model typically demands a more relaxed driving style. 

Just be aware that M Sport cars with bigger wheels can feel a little more stiff, but never uncomfortably so.

The engine range for the 4 Series Convertible has been frequently changed by BMW, with the final choices consisting of three petrols and three diesels. 

Petrol power begins with the 184PS 2.0-litre four-cylinder 420i, which delivers reasonable performance. Keener drivers will be drawn to the more powerful 430i, which produces a more substantial 252PS. It also uses a turbocharged 2.0-litre four-cylinder engine, and feels much more lively. 

Top petrol honours go to the 440i, which features an impressive 3.0-litre turbocharged straight-six. Its 326PS output makes the 4 Series feel genuinely sporty. 

The 2.0-litre 420d has a respectable 190PS to kick off the diesel engine range, and feels quicker than the petrol 420i. Next up is the 430d, with a chunkier 258PS improving performance even more. 

However, those in search of extra diesel power are likely to skip straight to the twin-turbocharged straight-six 435d. It comes with xDrive four-wheel drive as standard, helping manage all that power and torque. 

The 420d diesel comes with a six-speed manual gearbox, while the remainder of the engines use an eight-speed automatic.

The 4 Series Convertible has not been officially crash-tested by Euro NCAP. However, the related 3 Series saloon scored the maximum five-star rating when evaluated. With a host of airbags, and even pop-up roll bars behind the rear seats, we imagine the 4 Series Convertible would be equally safe. 

Front and rear parking sensors are fitted as standard. For those who need extra assistance, a rear-view camera (later upgraded to 360-degree surround-view) can be found on the options list. A Driving Assistance Package, featuring Lane-Keeping Assist and more, is also available. 

BMW uses run-flat tyres across the 4 Series Convertible range, meaning there is no spare wheel included.

Although a sporty convertible might not be the first choice for towing, BMW does offer the 4 Series with an official tow bar accessory for £750. 

Automatic diesel models offer the best towing ability, with their extra torque making light work of larger trailers. The 4 Series Convertible is rated with a maximum capacity of 1800kg for braked trailers, with this covering a number of the diesel-engined cars. Unbraked towing capacity is limited to 750kg.

Legroom is particularly restricted in the back, although head and shoulder space are more acceptable. Fixing child seats in the standard Isofix attachment points may be the most appropriate use for them. However, attaching the optional wind deflector will render the back seats completely unusable. 

A penalty for a folding metal roof is that it needs to be stored somewhere. For the 4 Series Convertible, that means robbing the boot of already limited space. Retracting the hard-top sees luggage capacity drop from a reasonable 370 litres to a far more meagre 225 litres. It means packing light if you want to travel roof-down.

BMW has a reputation for solid but sensible interior design, and the 4 Series Convertible is no different. It might not be particularly exciting, but all the trim components feel reassuringly expensive and high quality. 

‘Dakota’ leather upholstery is standard across the range, so there are no bargain-basement cloth seats here. Upmarket ‘Merino’ leather can also be specified as an option, along with a heated steering wheel. 

Satin silver interior trim is found on the entry-level SE model, with gloss black on Sport versions. Range-topping M Sport cars use an aluminium hexagon finish to cover the centre console and door trim.

Having been refined by BMW for nearly two decades, the iDrive multimedia system is one of the best in the business. A rotary controller on the centre console, combined with steering wheel-mounted controls, operates most of the infotainment. Displaying this is a screen mounted high on the dashboard, which comes in varying sizes dependent on the trim level.

All cars come with DAB radio, Bluetooth mobile phone connectivity and USB ports as standard. BMW is renowned for still charging to add Apple CarPlay, which costs £235 in the 4 Series Convertible. There is no support for Android Auto, either. Satellite navigation is part of the BMW ConnectedDrive package.

With BMW in the process of gearing up for the second-generation 4 Series Convertible, new examples of the original model may still be found in dealerships. This means you may need to be open-minded about engines and specification.

Pricing for the 2020 BMW 4 Series Convertible starts with the petrol 420i Sport at £39,220, which comes with the eight-speed automatic gearbox as standard. Diesel costs begin at £43,095 for the 420d Sport, although this comes with a manual gearbox. An automatic transmission increases the cost by £1,690. 

At the other end of the scale, buying the fastest petrol model will require £52,385 for the 440i in M Sport specification. The diesel 435d M Sport, including xDrive four-wheel drive, will require £54,470. This makes it the most expensive of all 4 Series Convertible models. 

Given the impending replacement of the 4 Series Convertible, BMW dealerships should be in prime position to offer good deals. Buying with PCP finance is likely to unlock additional deposit contributions to reduce the monthly cost. 

For example, BMW UK will contribute £3,500 to your deposit on a new 420i Sport, with the dealership adding a further £2,920. With a personal deposit of £2,500, this would see a monthly cost of £592 for a 48-month agreement. Mileage would be capped at 10,000 miles per year. 

Popularity means finding a used 4 Series Convertible should not be a challenge, and BMW dealers will have the latest manufacturer-approved cars. Diesel cars, in M Sport trim with automatic gearboxes, are the prevailing model on forecourts. 

Bagging a manufacturer-approved 420d M Sport Convertible, should cost from around £21,000 for cars with 20,000 miles or so. The more powerful 435d in the same trim will be closer to £28,000. 

Going petrol will see a 420i M Sport priced in the region of £22,000, with the 430i at £26,000.

The diesel 420d has become popular for a reason, offering the best overall fuel economy from the 4 Series Convertible range. Official figures show it being capable of averaging 47.1mpg, although this will vary slightly with specification. For comparison, the hot diesel 435d xDrive achieves a reasonable 39.2mpg in the same tests. 

As the least powerful petrol, the 420i has an official average fuel economy of up to 35.3mpg. Again, minor trim details will reduce this slightly. However, it manages to be only mildly more efficient than the much faster 440i, which averages up to 33.2mpg. 

Insurance costs for a premium convertible will be higher than average, with group ratings reflecting that. Being in group 32 (out of 50) makes the 420i Sport the cheapest to insure, with the diesel 435d M Sport the highest of all in group 42. The popular 420d M Sport is found in group 34.

From launch in 2014, the 4 Series Convertible has passed through several VED (road tax) regimes. Early examples of the 420d SE managed to score VED of just £30 a year.

Be aware that many of the cars sold after April 2017 fall into the £40,000 list-price category. This means they incur an additional £325 surcharge on top of the £150 annual VED rate. The is due for five years after the first year of registration.

BMW experimented with the trim levels available on the 4 Series during production. Modern and Luxury versions were offered from launch, but were phased out over time. Such cars are relatively rare in the used market. 

SE models have been the starting point for most of the Convertible’s life. These come with 17-inch wheels, dual-zone climate control and leather seats. 

Sport models feature larger 18-inch wheels, gloss black trim applied to the front and rear bumpers, plus sports seats and a Drive Performance Control switch.

M Sport is the consistent range-topper, and has proven popular with buyers. Standard equipment includes bespoke M Sport body styling, 18-inch alloy wheels and M Sport suspension. On the inside, a black headlining is complemented by leather sports seats.