BMW 4 Series Convertible review

We love a bit of innovation but sometimes traditional methods are best – as demonstrated by the BMW 4 Series Convertible.

You see, after switching to a folding metal roof for the previous-generation 4 Series Convertible, BMW has gone back to fitting a good old-fashioned fabric one.

Why? Well, a soft-top takes up far less space and means you no longer have to decide whether you want to fit the roof or your luggage in the boot (you can fit both). The 4 Series Convertible has also gained mild-hybrid engine tech, potentially improving efficiency and performance.

Like the regular BMW 4 Series, the soft-top version doesn't have many direct rivals, but if you're looking for wind-in-your-hair motoring, you might also be considering the Mercedes CLE Cabriolet, the Porsche 718 Boxster and even the VW T-Roc Cabriolet.

So how does the BMW 4 Series Convertible score against the best soft-tops for performance, interior quality, practicality and costs? Read on to find out…

The BMW 4 Series Convertible range kicks off with the 420i model, which uses a 2.0-litre turbocharged petrol engine producing 181bhp. It’s our pick in the BMW 4 Series and remains so here, because it should be brisk enough for most people and makes sense financially.

The 4 Series Convertible lugs around 165kg more than the coupé, so the engine does have a harder time of it here. As a result, it covers 0-62mph in 8.2 seconds (around a second slower than the 420i coupé) and feels quite flat low down, so it's just as well that it's happy to rev.

For stronger performance, there’s the 369bhp M440i petrol. It has four-wheel drive and delivers whip-crack acceleration (0-62mph takes just 4.9 seconds) while making a more soulful noise. Still want more power? Check out our BMW M4 Convertible review.

Whichever engine you choose, the 4 Series Convertible comes with an automatic gearbox that makes slick changes, especially in Sport mode. You can take control yourself using the shift paddles mounted on the steering wheel.

Lopping the roof off a car often makes its structure rather floppy, and while you’ll see the 4 Series Convertible's rear-view mirror wobbling sometimes, it takes a big bump for any shake to come up through the steering column. Thankfully, the steering remains as precise as it is in the regular BMW 4 Series, allowing you to place the nose of the car exactly where you want it.

BMW's M adaptive suspension is available as a standalone option regardless of which trim you go for, and we recommend adding it if you can. That lets you stiffen or soften the ride by selecting different modes, and even Comfort mode does an excellent job of propping up the body during hard cornering.

In fact, on pockmarked and uneven B-roads, Comfort is a better bet than the more focused Sport setting because its extra suppleness stops you from being bounced off course.  

It’s fair to say that the Porsche 718 Boxster is more involving to drive, but that car is smaller and misses out on the two rear seats. The 4 Series Convertible is better to drive than the Mercedes CLE Cabriolet and VW T-Roc Cabriolet.

Whichever driving mode you select, the car has an agility that's surprising given its extra weight compared with a regular BMW 4 Series. The ride is comfortable, even with big optional 19in wheels fitted. It rounds off all but the nastiest potholes, and deals with undulating tarmac with a great balance of comfort and control. This a car you’d happily cruise around in all day.

If you don’t tick the option box for adaptive suspension, the 4 Series Convertible comes with M Sport suspension, which gets relatively stiff springs and dampers. It makes the car feel like it's in the adaptive version’s Sport mode but doesn’t take away from the overall comfort.

When it's in place, the fabric roof does an excellent job of keeping noise down, with only a bit of wind whistling from around the front windows and engine noise that settles down when you’re not pushing on. Our only real demerit is that there’s a fair amount of road noise filtering up through the floor.

Impressively, if you drop the roof of the 4 Series Convertible but keep the windows up, you won’t arrive at your destination looking like your hair has had a close encounter with a hurricane. You’re even more protected if you fit the removable wind deflector, although you won’t be able to use the rear seats when you do.

For some extra luxury, you can add an optional Warm Air Collar – basically, vents in the front seats that blow warm air on to your neck. 

"As someone with long hair, I don’t usually enjoy convertibles for fear of being blinded by my fringe. The BMW 4 Series is different and never proves blowy with the roof down, even at motorway speeds." – Dan Jones, Senior Reviewer

When you're inside the 4 Series Convertible, you’d be forgiven for thinking you’d accidentally got into a BMW 3 Series. The driving position is almost identical, as are the dashboard and infotainment system.

In many ways, that's great news, because it means you get a comfortable and supportive driver’s seat with lots of adjustment, as long as you add optional adjustable lumbar support, which comes as part of the Comfort pack.

Forward visibility is good, and better than that of the Mercedes CLE Cabriolet, with much slimmer windscreen pillars that don’t get in the way at junctions.

Rear visibility isn’t great with the roof up because the rear headrests block much of the small rear screen, and there’s a lot of canvas obstructing the view over your shoulder. At least front and rear parking sensors come as standard on all models, along with a rear-view camera.

All versions come with bright adaptive LED headlights, which can maintain maximum illumination without dazzling drivers ahead of you. 

Build quality is first rate, with only the odd bit of hard plastic, most notably the bottom spoke on the steering wheel, and some silver-painted buttons on the dashboard letting the side down a little. It’s better overall than the Mercedes CLE Cabriolet and a definite step up from the VW T-Roc Cabriolet.

The driver gets a 12.3in digital driver's display, which shows lots of information and is positioned next to a 14.9in infotainment screen in the same housing.

You can operate the 4 Series Convertible's infotainment screen as a touchscreen or by twisting and pressing a rotary controller between the front seats, making it less distracting to use while driving, compared to touchscreen-only systems like in the CLE Cabriolet. Annoyingly, adjusting the temperature and climate control system is more fiddly than before (the latest facelift got rid of user-friendly physical buttons below the air vents).

The infotainment system has plenty of features, including Android Auto and wireless Apple CarPlay smartphone mirroring, along with a DAB radio and built-in sat-nav, but that means the main menu is pretty overwhelming. Luckily, the system reacts quickly to your inputs and has permanent on screen shortcuts to all the parts you’ll use the most, helping to simplify things. 

"If you’re into your music, I think you’ll definitely want to add the optional Harman Kardon stereo system. It’s arguably one of the best systems out there, giving plenty of depth to your music." – Dan Jones, Senior Reviewer

Practicality isn’t going to be a top priority when buying a two-door convertible car like the BMW 4 Series Convertible, but the chances are you occasionally need four seats and a boot that can swallow more than just a shoe box.

There’s as much space up front for occupants in the 4 Series as you’d get in a BMW 3 Series so you’re unlikely to have any problems with head or leg room. That includes storage space as well, with a big glovebox and a decent cubby under the centre armrest.

There's a useful lidded storage area in front of the gear selector, where you’ll find a couple of generous cupholders and a space for your phone and keys. You also get partitioned door bins so loose items don't roll around.

Getting into the rear seats involves squeezing through a relatively narrow gap, but the same is true of all four-seat convertibles. Once you’re in, you’ll find acceptable leg room.

Taller adults will need to cower slightly or put up with their heads resting on the underside of the roof, but a couple of six-footers will be comfortable enough in the back as long as the journey isn’t too long. BMW gives you a couple of cupholders back there but the other storage areas are pathetically small.

The boot capacity is slightly smaller than in the BMW 4 Series Coupé and – as with most convertibles – offers more space with the roof up than with it down.

There’s still space for up to six carry-on suitcases and you can fold down the rear backrest using a handy lever in the boot. Unlike in the coupé or the Mercedes CLE Cabriolet, the seats don't split and fold down for greater storage flexibility, but there is a cubby behind them where you can store the optional wind deflector vertically.

"I think it’s quite impressive how much space you have when sitting inside the BMW 4 Series Convertible, especially in the front." – Dan Jones, Senior Reviewer

The BMW 4 Series Convertible costs more than a coupé BMW 4 Series but less than a Mercedes CLE Cabriolet. The VW T-Roc Cabriolet is much cheaper but nowhere near as good to drive.

It’s worth noting that, compared with those rivals, the 4 Series Convertible is predicted to lose its value slightly faster. That can have an effect on the amount you’ll pay on PCP finance.

Entry-level M Sport trim comes with plenty of kit, including 18in alloy wheels, leather seats (heated in the front), cruise control and three-zone climate control. It’s our recommended trim. In terms of options, it’s worth paying extra for adjustable lumbar support and M Adaptive Suspension.

Sitting above the M Sport is the range-topping M440i. It gets similar equipment to the entry-level car but adds the more powerful engine and an M Sport differential, sportier styling and different 18in alloys. You’ll want to add adjustable lumbar support and adaptive suspension.

The 4 Series Convertible did quite well in the 2024 What Car? Reliability Survey, finishing in the top 10 best petrol cars aged up to five years old. BMW claimed eighth place out of 31 brands, placing it above Volkswagen, Porsche and Mercedes. 

BMW gives you a three-year/unlimited-mileage standard warranty, which matches what you’ll get with the Mercedes CLE Cabriolet.  

The safety testers at Euro NCAP gave the 4 Series Convertible five stars out of five in 2019. It scored well, partly thanks to the model's standard collision-prevention equipment, including automatic emergency braking (AEB).

For more safety kit, you can also add the Driving Assistant as part of the optional Technology pack, adding lane-departure warning, rear cross-traffic warning, automatic speed-limit recognition and an upgraded AEB system that can recognise pedestrians as well as cars.

"The BMW 4 Series Convertible is pretty well-equipped as standard, even in our favourite entry-level version, but I think it's annoying that you have to add lots of things as optional extras – especially adjustable lumbar support with the already expensive M440i." – Dan Jones, Senior Reviewer

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