Words: Calvin Chan
Photography: Calvin Chan
Published: July 15, 2021
The 2021 BMW 4 Series is no stranger to controversy but once you get over the front kidney grill, you will find an impressive sports convertible that delivers the goods on all fronts. Larger, wider, and higher than the outgoing model, the new 4 Series Convertible has also lost weight by ditching the hard-top roof in place of a fabric soft-top that is 40% lighter. And while the silhouette loses some aesthetic appeal, fabric roofs are so well made and insulated these days that the list of penalties are few. The soft-top saves weight, increases trunk space, adds extra headroom, and significantly lowers the car’s center of gravity for better performance.
The result is a clean and attractive shape, assisted by the frameless windows, a long hood, and minimalistic lines. One advantage of the convertible is that there is no B-pillar, so rolling down both front and rear windows allows for a wide moon-shaped opening, a nifty alternative to open-air cruising during light rain or under heavy sunlight. The 4 Series looks spectacular in Frozen Portimao Blue as well, a $4,900 paint option, and the rear-end and three-quarter proportions make it easily one of the best looking convertibles to wear the roundel badge. Shame that the fabric roof is only available in black, though.
Like the Ford Mustang GT and Mazda MX-5, the 4 Series Cabriolet offers a rare feature: rear-wheel drive. The Mercedes-AMG C 43 and Audi S5 are four-wheel driven only. All-wheel drive will be available for the 4 Series later in the year, but axing the front driveshaft helps to counteract some of the weight penalty from the roof’s complex internals. The RWD model should also yield better fuel economy numbers, better steering, and would be a suitable third or fourth seasonal car when AWD traction isn’t warranted.
Launched in two flavours, the 430i receives a 2.0-litre turbocharged four-cylinder (B46) that punches out 255 hp and 294 lb-ft, while the sportier M440i on test here is equipped with the more potent 3.0-litre turbocharged inline-six (B58) that generates 382 hp and 369 lb-ft of torque. The M440i is further paired with a mild hybrid system much like in the Audi RS6, that utilizes a 48-volt starter generator unit and a 48-volt battery. They tag team together to butter up the engine’s start stop operations, it allows the engine to be shut off when cruising and when coming to a halt, and it effectively marries the powertrain together into an wholesome and impressive unit. Six-cylinder engines don’t get much more polished than this, and it’s further backed up by the 8-speed ZF automatic gearbox that we have praised in nearly every BMW application for being one of the best and smoothest gear shifting companions.
With a broad powerband and ample low-end torque, the M440i is effortless to drive and is enough for a 0-100 km/h sprint in 5.2 seconds. Being rear driven means the M440i isn’t terribly quick in a straight line but the power feels accessible, exploitable, and should be sufficient enough for most drivers. The output is not overkill either, so you don’t have to constantly check the speedometer in fear of accidentally reaching impounding speeds. The 8-speed reacts swiftly and is tuned with decently stacked ratios for road use. We don’t feel the mild hybrid system very much during daily use but turbo lag is pretty much undetectable and non-existent, with just the tiniest of vibrations when the engine fires back to life.
Furthermore, the exhaust sounds provided by the straight-six are harmonic and melodic, and lack those somewhat immature pops and burbles on overrun. Though, opting for the optional M Performance Exhaust will fill in that void if you so choose. Otherwise, the volume is appropriate for a mature, sporty convertible, and never shouty and in your face like a Jaguar F-Type.
For reference, this M440i Cabriolet weighs 115 kg more than the 430i Cabriolet, 88 kg more than the M440i xDrive Coupe, but is more importantly 72 kg less than the last-generation 440i xDrive Cabriolet. Despite that, the M440i drives well and is more rigid than before, but still heavy. You can feel that heft when slinging around corners at speed. Traction is good but grip becomes scarce when the tarmac gets slippery, forcing the traction control light to flash incessantly. The M440i rides on passive dampers, meaning they are not adaptive or adjustable via driving modes, which we prefer. The resulting road comfort is exceptional, floaty enough for long distance cruising, yet stiff enough to never convey any structural weaknesses or loss of rigidity versus the coupe.
With the size increase and minimal amount of wind turbulence seeping into the cabin, the 4 Series actually feels like the larger, outgoing 6 Series. Sound deadening is impressive when the roof is up, and even more impressive when down. We also had no issue having regular conversations with our passengers at triple digit highway speeds, something we always struggled with in the rivaling C 43 and Mustang GT. The BMW doesn’t even need the attachable wind deflector either - it’s that good. On a side note, the roof can be electrically operated at speeds up to 50 km/h, and takes about 18 seconds to complete its mechanical dance.
Mimicking the 8 Series, the 4 Series interior is ergonomically sound and will be familiar to anyone that has spent time in a modern BMW, from the beefy steering wheel that’s like wrestling an anaconda, to the exquisitely supportive seats that look great and come with the Air Collar feature that blows hot air around your neck, should the ambient temperature begin to dip. It also comes with an automatic seat belt extender that makes life easier.
The touch points feel exceptionally premium, from the aluminum-esque window switchgear to the buttons surrounding the gear shifter. The infotainment buttons don’t have the most positive feedback and sometimes need a second press to secure the prompt but it is still the gold standard of infotainment units, utilizing touchscreen, rotary dial input, and an impressive voice recognition system that learns and adapts. BMW also seems to have listened to customer feedback and have made its wireless Apple CarPlay and Android Auto features standard fare.
Swollen dimensions may be a detriment when it comes to performance but it actually pays dividends to rear seat space in the M440i Cabriolet, which can now comfortably fit average-sized adults. My six-foot figure still finds it a bit cramped, and the rear seats are elevated above the front seats, which means you will be eating bugs if you keep your mouth open, but it’s entirely usable for short journeys around town.
Trunk space is quite poor but acceptable by convertible standards. It’s nowhere near as spacious as a Mustang’s, and the entry portal is still narrow and intrusive but the depth of the trunk is more than before and should be enough for groceries or luggage for a two-person weekend getaway. The two rear seats add another layer of storage as well.
The BMW M440i Cabriolet is a wonderfully competent boulevard cruiser that focuses more on comfort and luxury amenities rather than downright performance despite the flurry of M badges. It has grown in size and lost some weight with the addition of the soft-top roof, serving to augment the 4 Series’ strengths with impressive road manners and significantly reduced cabin turbulence.
Model: 2021 BMW M440i Cabriolet
Paint Type: Frozen Portimao Blue
Base Price: $72,750
Price as Tested: $87,450
Length/Width/Height (mm): 4,775 / 1,851 / 1,386
Curb weight (kg): 2,892
Engine: 3.0-litre turbocharged inline-six
Horsepower: 382 hp @ 5,800 - 6,500 rpm
Torque: 364 lb-ft @ 1,800 - 5,000 rpm
Transmission: 8-speed automatic
Engine & Drive Configuration: Front engine, RWD
Observed Fuel Consumption (L/100km): 11.8