BMW 4 Series Convertible Review
Mixing four-seat practicality with open-top thrills and a great range of engines makes the 4 Series Convertible an appealing overall package
Strengths & weaknesses
Open-top cars can be great fun – the sun on your face and the wind in your hair can transform even the most mundane of journeys into a memorable occasion. Many convertible cars are two-seaters only, however, and often have little in the way of luggage space. That’s not the case with the 4 Series Convertible, though, which offers fresh-air motoring for four, plus luggage.
The version of this car that BMW made between 2014 and 2020 featured a folding metal hard-top, but this version reverts to fabric for its roof. Part of the reason for this is weight, and the other element is packaging; not only is a folding fabric hood lighter - improving fuel economy and performance - but it also takes up less space when folded down, leaving more room for rear passengers and luggage.
The attention-grabbing front end of the car might be a little brash for some tastes, but like the 4 Series Coupe, the overall styling is sleek and suitably sporty. It’s arguably a little more striking than the model’s main rivals, the Mercedes C-Class Cabriolet and Audi A5 Cabriolet.
The engine options for the 4 Series Convertible mirror those of the 4 Series Coupe, and are similar to those available in the 3 Series Saloon. This means there are two 2.0-litre turbocharged petrol engines - the 184hp 420i and the 245hp 430i - plus the 190hp 2.0-litre diesel 420d. There are also 3.0-litre six-cylinder diesels with 286hp and 340hp, plus a 3.0-litre M440i xDrive, which has a substantial 374hp.
Despite the fabric roof, the 4 Series Convertible does weigh notably more than the equivalent 4 Series Coupe, due to the need for extra body strengthening in order to make up for the loss of structural rigidity in having no fixed metal roof. It’s not too bad in the case of the 4 Series - around an extra 165kg compared with the coupe model.
This does blunt acceleration a bit, but the 420d can still manage 0-62mph in a perfectly nippy 7.6 seconds, while the M440i can manage it in a rapid 4.9 seconds - as quick as you’d expect of a fast hot hatch such as the VW Golf R. The fact that most of the engines get mild-hybrid technology helps here, as it gives a small performance and fuel-efficiency boost.
Every 4 Series Convertible is fitted with a smooth eight-speed automatic gearbox - there is no manual option here. Most models are also available with 'xDrive' four-wheel-drive for extra traction, and it’s standard with some models - such as the M440i.
Like the regular 4 Series Coupe, the convertible version is still excellent fun to drive. So even though it’s heavier and its body is a little less rigid than the coupe (which makes it feel less agile to drive), it still feels sportier than the 3 Series Saloon.
The entertaining driving experience is partly down to the adaptive suspension, which is standard on the M440d and M440i, and an optional extra with other trim levels. It lets you switch between firm, sporty suspension settings and softer, more comfort-focused modes.
The interior of the 4 Series Convertible will be very familiar indeed to anybody who’s spent time in a 3 Series. This is because the dashboard, touchscreen media system and digital driver’s display (which is a digital replacement for a traditional speedometer and rev counter) are all identical to those in the 3 Series and 4 Series Coupe.
That’s good, though, because the large, clear touchscreen has very little lag, and the 'iDrive' media system, which uses a mixture of a rotary controller and buttons, means you can make adjustments to the entertainment system or sat-nav while on the move while barely taking your eyes away from the road.
As with the 4 Series Coupe, you sit lower to the ground than in a 3 Series (or indeed the car’s rivals from Mercedes or Audi), emphasising the feeling of sportiness. The BMW also feels like a higher-quality product in terms of build quality than the Mercedes, but it can’t quite match the feeling of solidity you get from the Audi A5’s interior.
High-spec M Sport is the only core trim choice. This includes plenty of standard equipment, such as a digital radio, Bluetooth phone connectivity, Apple CarPlay and Android Auto smartphone mirroring, heated leather seats, three-zone climate control and cruise control. You can also upgrade to the M Sport Pro Edition, which adds larger 19-inch alloy wheels, plus the clever adaptive suspension system.
Technically speaking, the M440d and M440i are separate trim levels, but they are essentially the same as the M Sport Pro Edition package, albeit with more powerful engines. At the very top of the tree is the M4 Competition, which gets a significantly upgraded chassis, aggressively sporty styling and a 510hp power output from its potent 3.0-litre engine. It’s also significantly more expensive than any other 4 Series Convertible.
Two areas where the convertible 4 Series differs from the coupe model are rear-seat space and luggage room. The rear seats get restricted headroom when the roof’s up, and the need to find space for it to be stowed away when folded means rear legroom is also tight. The same goes for the boot, which at 386 litres is 55 litres smaller than the Coupe’s. That being said, both the rear seats and boot are perfectly acceptable for this type of car.
Should I get a BMW 4 Series Convertible?
✔ Great to drive for a convertible
✔ Rides well, especially with adaptive suspension
✔ Well designed and solidly built interior
✘ Lack of entry-level models makes it pricey
✘ Rear seats are a squeeze for adults
✘ No plug-in hybrid or electric version
If you want wind-in-the-hair fun, plus usable rear seats and a decent-sized boot, then the 4 Series Convertible is great - it handles all those tasks with aplomb. Better still, despite a slight weight increase over the equivalent coupe model, it’s still genuinely entertaining to drive - and almost as fun as two-seater rivals such as the Porsche 718 Boxster.
It’s also impressively quiet on the move with the fabric hood up - you could almost imagine you were in a car with a fixed roof, so effective is it in shielding you from the outside world.
It’s not cheap to purchase, but then few models in this category are, and the 4 Series counters this with excellent levels of equipment as standard. Plus, as it’s a desirable model, it should hold onto its value pretty well, too. This means that cash buyers should get a decent amount back when they come to sell and those who opt for PCP finance should have lower monthly payments than with a similarly priced car that loses value more quickly.
- Models explained
- Trim levels
- Best BMW 4 Series for...
- Boot space
- Should I buy used?
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BMW 4 Series Convertible
This version of the 4 Series Convertible does away with the bulky folding metal roof of its predecessor in favour of a more traditional fabric hood. This takes up less space when folded away and is lighter, offering a clear advantage when it comes to fuel efficiency.
Also like the previous version of the car, this model shares much of its technology, interior design and engines with the BMW 3 Series saloon. However, just like the 4 Series Coupe, it’s designed to be more sporty-feeling and more glamorous than the more everyday, business-like 3 Series.
BMW M4 Competition Convertible
The M4 comes in both coupe and convertible versions. In the case of the convertible model, it uses the regular soft-top 4 Series as a starting point, but it features larger wheels, more overtly sporty styling and some very bright paint colour options to set it apart from the regular 4 Series Convertible.
However, what really makes the M4 stand out is its 3.0-litre turbocharged six-cylinder engine, which develops 510hp and is enough to catapult the M4 from 0-62mph in a rapid 3.7 seconds. That’s a little slower than the four-wheel-drive version of the M4 Coupe, but then the convertible is 145kg heavier.
The M4 Convertible is also available with xDrive four-wheel-drive only - unlike the coupe model there’s no rear-wheel-drive choice. The only gearbox option is an eight-speed automatic. But as this is fast and smooth-shifting, most drivers should be pretty happy with it.
|M Sport||From £17,950: M Sport is the only trim level in the 4 Series Convertible - there are no more basic trim versions as in the BMW 3 Series. This means that equipment levels are impressive, including heated seats trimmed in leather, cruise control and three-zone climate control.|
|M Sport Pro Edition||Limited stock: M Sport Pro is effectively an equipment package that sits on top of the regular M Sport trim. It brings larger 19-inch alloy wheels and adaptive suspension, among a few other choice goodies.|
Every engine option you can go for in the BMW 4 Series Convertible is impressive, with a good balance between fuel efficiency and performance. The best of the lot, though, is the M440i xDrive’s 3.0-litre turbocharged six-cylinder engine.
Standard four-wheel-drive and a significant power output of 374hp, mean it’s capable of 0-62mph in a rapid 4.9 seconds, yet you should be able to achieve fuel economy of around 35mpg easily enough, and a 40mpg run should be possible with a gentle motorway cruise. Oh, and the exhaust sounds fantastic, too, if you like to hear a little noise from the car.
A varied choice of petrol and diesel engines at a range of price points means there is a 4 Series Convertible to suit all sorts of motoring tastes.
|BMW 420d: A diesel might not seem the most glamorous choice for a convertible car, but the 190hp 2.0-litre engine in the 420d is seriously impressive. It has enough power for overtaking and effortless motorway cruising, yet can also achieve 57.6 mpg, which you’ll definitely appreciate at the fuel pumps.|
|BMW 420i: If you’re not doing huge mileages, the entry-level 420i petrol probably makes the most sense. It’ll still give you around 40mpg fuel economy, but is a few thousand pounds cheaper to buy. No four-seat convertible makes a perfect family car, but the 420i offers a reasonable blend of power, economy and value.|
|BMW M440i xDrive: Strictly speaking, the M4 is the fastest 4 Series Convertible, but it’s seriously expensive and is something of a standalone model of its own. Compared with that, the M440i xDrive almost seems like a bargain, and with 374hp it’s pretty much as fast as the fastest hot hatches.|
|BMW 430i: In isolation, there’s absolutely nothing wrong with the 2.0-litre petrol 430i. However, if it’s fuel efficiency you want, then it's best to go for the 420d, and if it’s power you crave then the 440i will be far more appealing. Meanwhile, the 420i is a better all-rounder.|
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The primary rivals for the BMW 4 Series Convertible are the Mercedes C-Class Cabriolet and the Audi A5 Cabriolet. When it comes to interior design, the Mercedes seems a bit flashier, but actually feels a little less well built than the BMW, while the Audi feels even more upmarket than the 4 Series.
The 4 Series Convertible is the one to go for if you want a sporty driving experience, however. Both the A5 and the Mercedes feel more focused on delivering a comfortable driving experience as opposed to a sporty one.
If none of the German trio appeals to you, then the American-as-apple-pie Mustang Convertible could be up your street. It’s less restrained in its styling than most other options, but its iconic muscle car looks, plus the option of a beefy V8 petrol engine, make it an appealing prospect. It’s several thousand pounds cheaper than the BMW, too.
And if you don’t need rear seats at all, then something more overtly sporting such as the BMW Z4 or Porsche 718 Boxster is worth a look.
BMW 4 Series Convertible practicality: dimensions and boot space
The BMW 4 Series Convertible is identical in its key dimensions to the coupe version. This means that it’s 4,768mm long, 1,852mm wide (just over 2m wide when you add in the door mirrors) and 1,383mm tall. Like the Coupe, this makes it lower and wider than the 3 Series Saloon, contributing to its sporty-looking stance.
It also means that it shares almost identical vital statistics with the Audi A5 and Mercedes C-Class Cabriolet. So, as with those cars, it’s quite large and the rearward visibility isn’t good at all with the hood up. Fortunately, standard parking sensors address the main potential issues in tight car parks.
But while those dimensions allow for plenty of interior room in the coupe, the need to store the fabric hood eats into both boot space and rear-seat room in the Convertible. As a result, while the 4 Series Convertible is practical for a convertible, it falls behind coupe alternatives and similarly sized models with four or five doors.
|Length 4,768mm||Width 1,852mm|
|Height 1,383mm||Weight 1,690kg - 1,995kg|
Take out the need to store the fabric hood somewhere, and the 4 Series Convertible would have a rather spacious boot - the Coupe offers 440 litres of space, for example. Unfortunately, in the case of the Convertible, this is reduced to 385 litres of space. That’s still pretty good - more than you get in a Volkswagen Golf or Ford Focus for example.
However, those are much smaller cars and when you do stow the roof away, boot space drops to 300 litres. Overall, the 4 Series Convertible still trumps the C-Class Cabriolet for boot space, but the Audi A5 Cabriolet is more practical still.
|Boot size 385 litres|
Premium car makers can sometimes - perhaps surprisingly - perform quite poorly in owner satisfaction surveys. The BMW 4 Series is a case in point: out of the 75 car model ranges surveyed in the 2021 Auto Express Driver Power survey, the 4 Series came in a lowly 56th.
Given that the 3 Series Saloon achieved 31st place in the same survey, that is even more of a shock. That said, most owners' issues were electrical and trim niggles rather than catastrophic call-the-tow-truck breakdowns, so a 4 Series Convertible should deliver reasonably dependable open-top motoring.
As standard, the factory warranty from BMW covers you for three years - which is fairly unremarkable. What’s surprising is that there is no mileage limit during this time, while with Mercedes or Audi the mileage limit is 60,000 miles on a three-year warranty.
As a result, high-mileage drivers after a relatively new car could get warranty cover for more miles with the BMW than Mercedes or Audi alternatives. If you want a longer warranty, Renault and Hyundai offer a five-year warranty from new, while Kia and MG will give you seven years of cover.
|3 years||Unlimited miles|
AVERAGE REPAIR COST PAID BY WARRANTYWISE: £721
The BMW 4 Series Convertible is not especially cheap in terms of its basic list prices. It also holds onto its value quite well, too, which makes the price of used examples quite high too. However, this does mean that cash buyers should get a decent amount back when they sell the car on and PCP finance monthly payments can be quite low, since the value of the car at the end of the contract plays just as big a part in shaping monthly payments as the initial price.
Despite the fact that the BMW diesel engines available in this version of the 4 Series Convertible meet the latest - very strict - emissions regulations, the move towards electric and hybrid power means that diesel versions are likely to be much less common than petrol models. But if you do a lot of miles - particularly on the motorway - they are still worth seeking out, as they provide very impressive fuel economy, especially the 420d.
BuyaCar prices from £17,950
BuyaCar prices from £17,950
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Any 4 Series Convertible you choose will be well equipped. You’ll get three-zone climate control, built-in sat-nav, heated leather seats and an eight-speed automatic gearbox, among other goodies.
This means that the best model for you to choose will be down to its engine. In that context, the diesels make most sense if you’re a high-mileage driver, while the M440i xDrive is great if you have more to spend and want a faster car that doesn’t sacrifice everyday usability or use too much fuel. Meanwhile, the 420i is a good value all-rounder for those who don't do enough miles to warrant a diesel.
*Representative PCP finance - 2018 Ford Fiesta 1.0 ST-Line Hatchback:
|PCP representative example||APR rates available|
|Cash price £12,000||APR 7.90%||Value of loan||From|
|Fixed monthly payment £218.12||Annual mileage of 8,000pa||£25,000+||6.9%|
|Total cost of credit £2,755.55||Term 48 months||£12,000-£24,999||7.9%|
|Optional final payment £4,285.79||Loan value £12,000||£8,000-£11,999||8.9%|
|Total amount payable £14,755.55||Deposit £0||<8,000||9.9%|
BuyaCar is a credit broker, not a lender. Our rates start from 6.9% APR. The rate you are offered will depend on your individual circumstances.
If smart looks are more important than practicality, and you want a premium badge and a fun driving experience, a 4 Series is worth a look
A fun driving experience, strong engine lineup and an unusual folding-metal roof set the BMW 4 Series Convertible apart
Is it a saloon? Is it a coupe? It’s both – but does that make it the best 4 Series for you?
Dramatic looks, a great range of engines and a fun driving experience help the BMW 4 Series Coupe to stand out