TEST DRIVE: 2021 BMW 4 Series Convertible – Looking Past The Kidney Grille

A fun weekend cruiser with polarizing looks, but good performance

Launched late last year, the drop top version of the second generation 4 Series comes with a lot of controversy in its tiny boot. As if the front-end and its huge grilles wasn’t enough, the new drop top also comes with a huge change at the back, where the folding top is no longer made of metal. That’s right, the new 4 Series Cabrio comes with a soft top. Cue sad music.

For some people this will be welcome news while others will complain about BMW “cheaping out” and forgoing the metal roof.  But in my opinion, the soft top makes a lot more sense since it’s lighter and, personally, I think it gives the car a bit more character.

Sleek Lines, But A Massive Kidney Grille

Over the years, the drop top version of the 3 Series had a lot of different solutions deployed. Most of them were soft tops, but there were exceptions as well. For example, the E46 generation drop top could be had with an optional hardtop, which wasn’t retractable, but could be used during winter months, replacing the soft top altogether. Then came the E93 3 Series Cabrio, the grandfather of the current 4 Series Cabriolet, if you will. It was the first model with a folding hardtop in the 3 Series’ history and set the first generation 4er to a great start as it used a similar solution.

Now, the time has come for yet another change. Will this be the final one? Will we see BMW return to a hard shell in the future? Only time can tell. However, the solution chosen by the Munich-based car maker is a very interesting one, nonetheless.

TEST DRIVE: 2021 BMW 4 Series Convertible – Looking Past The Kidney Grille
Polarizing Front-End

On the design side of things, the 4 Series Convertible doesn’t change a lot up front. It still has the same huge grilles that dominate the fascia, along with the new, sleek headlamps that, in this case, were fitted with laser light technology. They do look cool, especially since they get the full Corona rings around them and those blue elements right in the middle. As for the grille, it has been dissected so much, we won’t dwell on it: either you like it or you don’t. Apparently, there’s no middle ground left for it anymore.

Longer, Wider And Lower

TEST DRIVE: 2021 BMW 4 Series Convertible – Looking Past The Kidney Grille
The Best View In The House

We can, however, discuss how the new 4er has changed compared to the outgoing model, and there’s a lot to unload here. Size-wise, the new convertible is now longer, wider and lower than the outgoing one. At 4,768 millimeters, it is 128 mm longer than its predecessor, while width has increased by 27 mm to 1,852 mm and the wheelbase has grown by 41 mm to 2,851 mm. The vehicle height is 1,384 mm with the roof closed.

Increased track widths (+ 28 mm at the front and + 18 mm at the rear) accentuate the car’s muscular stature, which can be noticed even more than on the Coupe version, especially at the back. With the roof folded, the wide hips of the 4 Series Convertible really stand out. Of course, having a wide track also comes in handy when driving fast.

It’s from the side that you’ll probably appreciate the 4 Series Convertible the most though, especially with the roof folded. It has simple yet powerful lines all around, and with the textile roof hidden away in the boot, you’ll only focus on the other aspects of the car, from the raked windshield, to the large open area in between the rear headrests and the taillights.

The big change though, is the roof, as I already mentioned. It is now a more conventional choice, done in hopes of reducing the overall weight of the car. Compared to the previous-generation, the current 4 Series Convertible has a roof that’s now 40 percent lighter. This way, the car also benefits from almost perfect 50:50 weight distribution, if we’re not talking about the 6-cylinder versions.

The soft top’s new panel design comprises large panel bow elements with a paper-honeycomb construction, a flush-fitting glass rear window, several layers of insulation and a fabric cover available in two colors. The soft top pulls taut over the passenger cell when closed, with the fabric material lying flat on the joint-free arrangement of adjacent panel bow elements. This way neither their contours nor the soft top frame shows through the surface and the result is a coupé-like roofline with a purist soft top feel.

Having a smooth surface isn’t all about the looks though. This ensures a low drag resistance factor too, making the car more aerodynamic. That’s not necessarily meant to improve the fuel consumption, but mainly to reduce the wind noise perceived in the cabin at higher speeds. And it actually works, this being a very quiet car with the roof up, for a soft-top solution.

TEST DRIVE: 2021 BMW 4 Series Convertible – Looking Past The Kidney Grille
Soft Top

The motion the roof goes through when you open or close it is different too. Now, the whole thing creates a ‘Z’ shape when folding, stacking the three main pieces of the roof one on top of the other and neatly folding them in the back. The whole process takes around 18 seconds, according to BMW, and you can do it at speeds up to 50 km/h (31 mph) which is an improvement over the last generation 4 Series. Of course, just like it was the case on the old one too, the windows are automatically raised when the process is done.

On top of the 40 percent weight reduction, the new roof also takes up less space in the boot. Therefore, you now have access to 300 liters of space in the boot, 80 more than in the previous-generation model. That may sound like an impressive upgrade but, it’s worth mentioning that the opening of the boot is rather small. If you’re planning on carrying stuff in there, you might want to make sure it will fit under the allotted space for the roof.

However, one interesting trick BMW implemented, is the possibility of adjusting the soft top compartment’s flap. This way, when the roof is up, you can gain access to up to 385 liters in total. As standard, you get a ski hatch in between the rear seats, in case you want to go skiing or maybe carry longer items.

Another novelty for the 4 Series convertible is the possibility of configuring it with two different color choices for the textile roof. You can go with a classic black finish or you can have it with an Anthracite Silver effect finish which does look pretty sharp.

Technically A 4-Seater, Practically For Two People

Inside the cabin there aren’t many differences compared to a regular Coupe model. Everything seems exactly the same up front but you will notice the lack of a B-pillar, which creates a sensation of space when sitting in the car. It also makes getting in the back a lot easier, as you can roll down the windows to help passengers out. However, there is a noticeably smaller and more cramped feeling in the back.

Theoretically, the 4 Series convertible is a four-seater but the rear seats would only work for… smaller humans. Their seatbacks are also a bit more upright, making longer journeys a bit tedious. Furthermore, the same old wind deflector solution was deployed by BMW for the new 4 Series drop top and that’s a bit disappointing.

While other car makers have created new solutions for this issue, BMW is sticking with a design that hasn’t changed a lot since it was first introduced on the E30 3 Series cabriolet. It’s the same two-piece mesh that gets fixed over the rear seats and basically nullifies them. Therefore, if you want to go on a longer trip, at higher speeds, you’ll have to choose: personal comfort or taking up to three people with you.

And that wind deflector truly makes a difference. Using it makes driving the 4 Series convertible rather comfy, without too much turbulence at speeds up to 110 km/h (68 mph) but if you remove it, you’ll notice that same threshold drops to about 80 km/h (50 mph). Raising the side windows will also help out a bit in this regard.

As it is always the case, if you also want to enjoy some great tunes on the way, you should probably go for the Harman Kardon top tier sound system available on the 4 Series convertible. I will point out that the hi-fi system we had on our tester delivered very good sound and it was rather impressive overall. It covered a wide range of frequencies and had a warm sound to it. Its only issue was the volume, but I guess that’s why you get the Harman Kardon alternative.

Different Driving Experience Than The Coupe?

On the road, the 4 Series convertible feels a lot like its coupe brother. Some things have changed, as you would expect. Just like it is the case with any drop top, the body of the car had to be reinforced, to cope without a very important structural piece: its roof.

The extra bracing wasn’t just aimed at increasing the body’s rigidity but also the suspension. To this end, an additional pair of struts was installed for reinforcing the car’s rear. Other model specific features for the convertible include side skirts with extreme torsional rigidity, a double heel board, an aluminum shear panel low down in the front end, a reinforced transmission tunnel in the rear compartment and a likewise extremely rigid floor plate at the rear. As a result, static torsional rigidity of the new BMW 4 Series Convertible is up by four percent overall compared to its predecessor.

TEST DRIVE: 2021 BMW 4 Series Convertible – Looking Past The Kidney Grille
A Fun Cruiser

On the road, that translates into a slightly rougher behavior, especially over uneven or bumpy roads. The car feels a bit more unsettled over such surfaces, with the suspension having to work overtime to cope with the added weight and extra stiffness. Our tester was a 430i with a pure rear-wheel drive setup and it was a refreshing experience, to be fair, as most of the more recent BMWs I tested came with xDrive.

It’s nice to experience a rear-wheel drive model from time to time and the fact that I could get the tail out with my right foot did bring an occasional smile to my face. Under the hood of the 430i you’ll find a 2-liter petrol engine good for 245 HP and 400 Nm of torque. It’s a bit down from older 430i models because of the pesky emissions regulations BMW has to adapt to, but with a 0-100 km/h sprint of 6.3 seconds, this is a lively car.

It accelerates fast enough and I never really felt the need for more power. That doesn’t necessarily mean that the 382 HP M440i wouldn’t be welcome, but the 430i is decent nonetheless. I wouldn’t go for a less powerful version though, like the 420i or 420d, as this is a heavy car and you’ll end up wanting more when under hard acceleration.

The sound of the engine was rather surprising too, being quite noticeable, especially in Sport mode, with the roof down. For some reason, it didn’t sound like a traditional four-pot, but closer to a six-cylinder and the dreaded Active Sound Design feature might have something to do with it. The thing is, they implement this fake engine sound so well these days that’s becoming harder to separate it from what is actually coming from the exhaust, especially with the roof down.

There’s no understeer to talk about and the front-end has just as much grip as the coupe alternative would offer. The brakes on this M Sport model were also rather good, with a nice feel and good modulation throughout the whole pedal travel, while the steering could use a bit more feedback. Even so, there’s a lot of precision in it, and the moment you turn, the car behaves predictably, just as BMW got us used to. Carving canyon roads with this drop top will definitely be enjoyable.

Compared to the Coupe, the Convertible 4 Series does feel a bit more elastic, a bit less precise and that’s to be expected. After all, no matter how hard you try, when you don’t have the roof connecting the front to the rear end of the car, there are drawbacks. That’s not a big issue though, because on the new 4er, the differences are as small as they get. Some people might not even notice them at the end of the day.

A Safe Bet In The Segment

What you will notice though is the attention this car gets you. Whether people gawked at me because of the San Remo Green color on the outside, the white leather that was completely exposed with the roof folded or because of the huge grilles up front, I’ll never know. What I do know is that the 4 Series Convertible will offer a great open top experience and attract a lot of curious looks, making you the star of the show. If that’s what you’re looking for, this might just be the perfect car for you.

2021 BMW 4 Series Convertible

Exterior Appeal - 7.5
Interior Quality - 8
Steering Feedback - 7.5
Performance - 7
Handling - 7.5
BMWness/Ultimate Driving Machine - 7
Price Point - 7


What I do know is that the 4 Series Convertible will offer a great open top experience and attract a lot of curious looks, making you the star of the show. If that’s what you’re looking for, this might just be the perfect car for you.