by Gabe Beita Kiser
Since BMW diversified and turned the 3 Series Coupe into the 4 Series, fans of performance - and particularly the M division - only had eyes for what the M4 could achieve. Lighter and stiffer than an M3, it was set to be a true athlete; and since inception, it has been. But there exists a strange corner of automotive culture for enthusiasts who want a sharp driving tool, but they want it a little duller - they want the roof removed, the chassis softened, and the weight balance compromised for the sake of open-top cruising. BMW hasn't forgotten about the lifestyle enthusiast, and with the M4 Convertible, they've given these buyers a 425 horsepower, straight-six sports convertible to rival the Mercedes-AMG C63 Cabriolet. But, style and exclusivity don't come cheap; at a starting price of $77,650, the M4 Convertible is no budget machine. However, it could be argued that there are few better ways to enjoy a 4.2-second 0-60 mph dash than with the wind in your hair and an M-powered six-cylinder growl in your ears.
With the current 4 Series and M4 in their twilight years and a new generation ready to be unleashed for 2021, the 2020 M4 Convertible remains unchanged. Not even the prices have changed from last year.
3.0-liter Twin-Turbo Inline-6 Gas
For all intents and purposes, with the roof closed, the M4 Convertible looks largely like a standard M4 coupe. While all body panels for the 4 Series were completely redesigned from the 3 Series, the folding hardtop roof was a direct carryover from the E93-generation M3 Convertible. The rest of the M4 Convertible is standard M4, though, featuring aggressive front and rear bumpers with BMW's air curtain design, sleek kidney grilles up front, and sharply-styled LED headlights. The fenders are flared and house a set of standard 18-inch alloy wheels, while at the rear of the M4 Convertible, the signature quad tailpipes of all BMW M cars are housed within the M-specific diffuser.
The length and width of the M4 Convertible remain identical to the coupe's measurements of 184.5 inches and 73.6 inches, respectively, but the folding hardtop stands 0.2 inches taller at 54.6 inches overall. The M4 Convertible also borrows the standard 110.7-inch wheelbase and the 4.7 inches of ground clearance from the regular M4 Coupe, but differs when it comes to the curb weight and weight distribution. In manual guise, the M4 Convertible tips the scales at 4,110 lbs, while the automatic takes that figure to 4,165 lbs, representing a nearly 500-pound increase over the M4 Coupe.
While the rest of the world shies away from the manual gearbox, BMW steadfastly embraces it, giving buyers a standard six-speed manual gearbox with an optional seven-speed M Double Clutch Transmission. The gearbox choices are paired with a 3.0-liter turbocharged inline-six gasoline engine - dubbed the S55 - which, in convertible guise, develops 425 horsepower and 406 lb-ft of torque, and sends it exclusively to the rear wheels. The optional Competition Package elevates power outputs by 19 hp for a total of 444 hp. 0-60 mph takes 4.2 seconds with the DCT and 4.4 seconds with the manual. While the engine may be potent and the DCT adept at managing the peaky boost delivery, it's a pity a BMW straight-six sounds as uninspiring and characterless as the S55 does. It might be effective, but it lacks the soul a BMW six should possess.
While M cars typically get a firmer suspension, for the lifestyle appeal of the M4 Convertible, the mad scientists of Munich went soft. With less rigidity through the body and skewed weight distribution - approximately 48:52 front:rear while the M4 Coupe's balance is reversed - BMW wanted the M4 Convertible to ride a little softer to feel more cohesive. Of course, this means the M4 Convertible is nowhere near as sharp as its coupe sibling, but under regular use, you'd be hard-pressed to feel any loss of rigidity or any sense of additional weight. The car rides comfortably on most road surfaces, particularly with the standard 18-inch alloy wheels in play, and even with the roof down, the cabin is relatively quiet and wind free. Trouble arises when pushed beyond eight-tenths, though, as the search for dynamic prowess reveals flaws. The M4 Convertible's weight can't be hidden completely, and the numb steering belies the promises made by an M badge on the trunk.
You're unlikely to be too concerned with gas mileage when perusing the catalog of M-branded BMWs, but the M4 Convertible returns decent figures according to the EPA. In manual guise, claims of 16/22/19 mpg city/highway/combined are unimpressive, but the dual-clutch automatic remedies this with 17/25/20 mpg claims - an improvement over the coupe. The 15.8-gallon gas tank requires a diet of premium unleaded gasoline, which will yield an estimated range of 316 miles between stops.
BMW claims the M4 Convertible is a four-seater, but you'd be hard-pressed to get adults to agree with them. 40.4 inches and 42.2 inches of front head- and legroom, respectively, is more than ample for six-foot adults, while the 14-way power-adjustable M sport seats afford the driver an exceptional seating position. But those in the rear must make do with just 37.1 inches of headroom at a push, and 33.1 inches of legroom. That means more headspace than the coupe, but less knee room, relegating the use of the rear seats to children only.
While a maximum trunk volume of 13.1 cubic feet is claimed for the M4 Convertible, the more realistic figure is 7.8 cubic feet - that's how little you have left after the folding hardtop has been stowed away. Making matters worse is the fact that once folded, accessing the trunk requires an awkward dance of half closing the roof for better access; if not, you're left with a narrow sliver of an aperture. Fortunately, the rear seats double up as storage and can be folded for increased space, while a total of four cupholders, pockets on each door, a glove box, and a center console storage bin provide ample small-item storage. Keyless access also includes the hands-free opening of the trunk lid.
As the highest rung on the 4 Series Convertible ladder, the M4 Convertible gets a fairly impressive list of standard features. LED headlights, OLED taillights, a sport exhaust, and a power-retractable hardtop roof complete the exterior features list, while inside, buyers can expect 14-way power from M sport seats with lumbar support, memory, and three-stage heating, dual-zone automatic climate control, keyless entry, an auto-dimming rearview mirror, ambient cabin lighting, and a universal garage door opener. Other available features include neck-level heating and a heated steering wheel. Standard driver assists include a rearview camera, dynamic cruise control, lane departure warning, pedestrian and frontal collision warning, speed limit info, and city collision avoidance under the Active Driving Assistant banner. Additionally, the Executive Package adds surround-view cameras, a head-up display, automatic high beam functionality, and a parking assistant.
BMW's iDrive 7 infotainment interface is housed on an 8.8-inch touchscreen display, also controllable via the iDrive rotary controller on the center console. The system boasts standard AM/FM radio functionality, a CD player, Bluetooth and USB connectivity, SiriusXM satellite radio, HD Radio, and navigation with real-time traffic information. A 200 GB hard drive is also standard fit, while impressive audio quality is ensured by a 12-speaker Harman Kardon surround-sound system. BMW makes Apple CarPlay freely available for the first year, after which the system becomes subscription-based, but Android Auto is still absent.
The M4 Convertible and Coupe have both been subject to one recall for the 2020 model, in which 5,079 various BMW vehicles were affected by an improperly folded knee airbag that could potentially fail to deploy correctly in the event of an accident. The M4 Convertible is, however, covered by BMW's standard four-year/50,000-mile limited warranty and four-year/unlimited-mileage roadside assistance program.
Neither the M4 nor the BMW 4 Series on which it's based, have been evaluated for crashworthiness by the NHTSA or IIHS. BMW has, however, equipped the M4 Convertible with eight airbags including dual front knee airbags, as well as high-performance braking and stability control systems, lane departure warning, frontal collision warning and avoidance, and the availability of blind-spot monitoring, surround-view camera, and automatic high beams.
The standard M4 Coupe is sharp and precise, but devoid of emotion and driver involvement; the M4 Convertible is much the same. But, with the loss of its roof and the fitment of softer suspension, it becomes a more livable companion. The M4 Convertible still provides ample performance in a straight line and the ability to dissect a twisty piece of road, but it's become less edgy and more comfortable, ultimately suiting its character as a top-down luxury cruiser. However, it's still lacking in personality, missing a soulful soundtrack, and failing to involve the driver - despite the standard manual gearbox. It also loses out on practicality, not just because of the retractable roof, but because the hardtop hampers access to the trunk itself. The M4 Convertible is ultimately a competent but flawed machine and, when stacked up against the soulful Mercedes-AMG C63 Cabriolet, just doesn't feel special enough to leave a lasting impression.
The cost of getting behind the wheel of an M4 Convertible is $77,650, excluding options and a $995 destination and handling charge. In the lead-up to the M4's demise in its current form, BMW has elected to keep pricing for 2020 the same as it was in 2019. Options can, however, quickly send the price rocketing, with paint options costing up to $1,950, wheel options up to $1,200, and interior upgrades can set you back by $2,550. Options packages like the Executive Package cost $2,100, or if you'd like an extra 19 hp and a sportier package overall, the Competition Package adds $4,250 to the invoice.
The M4 Convertible is a standalone trim at the top of the 4 Series Convertible line-up, but with a range of options available, it can be easily customized. We'd spec ours without the Competition Package - as the convertible is more of a lifestyle vehicle than a hotrod - and likewise we'd steer clear of the $2,500 M Driver's Package and its raised top speed. Instead, we'd include the Executive Package for the head-up display, surround-view cameras, and fully adaptive LED headlights. We'd stick to the standard 18-inch wheels for the sake of ride comfort, and add neck-level heating, a heated steering wheel, blind-spot monitoring, and wireless charging. Despite what the purists might say, we'd also spec the M DCT automatic gearbox, as the manual isn't all that great. This takes the asking price to an all-inclusive $83,340.
Despite sharing a basic foundation, the M4 Coupe and Convertible take different approaches towards performance. Both are powered by the same 425-hp turbo-six engine, and both are rear-wheel-drive, but the M4 Coupe is more stiffly sprung compared to the convertible's softer setup. This, combined with less weight and more rigidity, makes the M4 Coupe a more talented athlete, capable of carving up canyon roads and racetracks alike. It also suits the Competition Package's enhancements better, making it a true driver's tool. On the other hand, the pricier Convertible gives you everyday performance in a more laid back style, letting you enjoy the wind in your hair and that boulevard-cruiser lifestyle appeal at the expense of razor-sharp handling and a practical trunk. The two types of buyers would never cross-shop, so at the end of the day, you just need to decide what type of shopper you are.
With no RS5 Convertible on sale in the US, the M4 Convertible has only one true rival - the Mercedes-AMG C63 Convertible. Both are compromised as sports cars by the loss of a roof, but the BMW suffers less from a handling perspective. Where it does suffer is in the hardtop's affinity for eating into practical trunk space, while the C63's soft-top is far more forgiving. The two differ fundamentally when it comes to attitude, though. The M4 Convertible is sterile and uninspiring - from the leafblower-engine note to the cold steering. The C63, on the other hand, has syrupy steering and an intoxicating soundtrack courtesy of its bi-turbocharged 4.0-liter V8 engine, while performance is vastly superior to the M4. It also feels more luxurious, and for similar money, it's the convertible that'll make you smile more and regret less.
Check out some informative BMW M4 Convertible video reviews below.