The all-new BMW 4 Series Convertible represents the latest chapter in the modern history of BMW Convertibles which dates back to 1987 and the first BMW 3 Series Convertible. As with the new BMW 4 Series Coupe, the 4 Series Convertible embodies the very essence of dynamics and aesthetic appeal in the premium segment. The “4” in its title headlines this new product line for the Convertible and emphasizes not only its stand-out design, but also the fact that any way you look at it, the new 4 Series Convertible represents something more than its BMW 3 Series cousins – 3+1, if you will. The 2014 BMW 4 Series Convertible will again feature a three-piece retractable hardtop with new features and functionality.
The new BMW 4 Series Convertible will be offered in the US as both a 428i, featuring BMW’s award-winning TwinPower Turbo 2.0-liter 4-cylinder and as a 435i with the multi-award winning TwinPower Turbo 3.0-liter inline six. Both will feature a standard 8-speed sport automatic transmission. The 428i Convertible will be offered with a choice of rear-wheel drive or with optional xDrive, BMW’s intelligent all-wheel drive system, while the 435i Convertible will be available at launch with rear wheel drive. The 2014 BMW 428i Convertible will have a base MSRP of $49,675, and the 2014 BMW 435i Convertible will have a starting price of $55,825. Both prices include $925 destination and handling. The 2014 BMW 4 Series Convertible will arrive in US showrooms in the first quarter of 2014.
The new BMW 4 Series Convertible is visibly larger in width and wheelbase than the outgoing BMW 3 Series Convertible, and its stretched silhouette sits considerably lower to the road. This, together with its BMW-typical short overhangs, long hood and set-back passenger compartment with flowing roofline, give the BMW 4 Series Convertible a visual balance. The car’s striking front end – with its characteristic BMW design features, such as the double-kidney grille, four round headlights and a large air intake in the front apron – is keen to display its family ties with the BMW 3 Series. New elements of the BMW 4 Series Convertible are the Air Breathers, which are positioned rearwards of the front wheel arches to reduce drag. The Convertible’s muscular wheel arches and wide track give an aggressive stance, with its prominent horizontal lines.
The design language of the new BMW 4 Series Convertible is reflected in the car’s unmistakable and elegant silhouette with balanced proportions when the top is down, and in the coupe-like profile of the roofline – without a B-pillar – when the hardtop is up. The three-piece retractable hardtop is distinguished by advanced soundproofing with its “noise-absorbing” headliner, ensuring quietness and passenger comfort under all weather conditions – even in winter. The interior roof is fully lined and features integrated lights that add to the ambience expected of a premium sport coupe. When the top is down and stored in the trunk, the standard load and unload assistance function moves the folded roof and the trunklid upwards to provide ample storage space and easy access. Even large and bulky items, like luggage or golf clubs, can be conveniently stowed when the top is down. The sound-absorbing headliner also reduces wind noise by up to 2 dB in comparison to its predecessor.
The interior of the BMW Series 4 Convertible presents a stylish fusion of sporty allure, elegance and exclusivity. All of the controls are arranged ergonomically around the driver to provide optimum access to all functions. The doors are designed so that all the lines converge towards the rear, and bright color combinations featuring a two-tone effect for the door and side panels, in combination with the hardtop cover, contribute to the “boat deck” look. This wrap-around interior design provides a cabin that allows all passengers to share the open-sky driving experience. The design of the stand electrically adjustable seats is new and, again, includes integrated seatbelts. If desired, the standard seats and the optional sport seats with recessed head restraints can be equipped with neck warmers for the driver and front passenger for the first time, as part of the available Cold Weather Package. When the top is down, the temperature setting is automatically controlled in relation to the outdoor temperature and the speed of the vehicle. In addition to the standard model, two specially equipped lines and M Sport are available in the US. The Sport Line and Luxury Line versions can be selected to personalize the new convertible with special interior and exterior accents. The fine materials and meticulous craftsmanship underline the premium ambience of the BMW 4 Series Convertible.
The defining characteristics of the new BMW 4 Series Convertible are its driving dynamics and aesthetics. As always, BMW engineers have placed special focus on steering accuracy, precision, linear control response, and agility to fortify the new BMW 4 Series Convertible as the latest shape of The Ultimate Driving Machine. Sophisticated chassis technology, near-perfect 50:50 weight distribution, fine-tuning in the wind tunnel, and lightweight construction all contribute to meet that goal.
The all-new BMW 4 Series Convertible has a longer wheelbase, wider track and lower ride height than the previous-generation BMW 3 Series Convertible. Its lower suspension brings down the car’s center of gravity. As a result, the new BMW 4 Series Convertible is inherently one of the sportiest open cars on the road.
In addition to its sporty driving dynamics, the new BMW 4 Series Convertible offers outstanding fuel efficiency. This is a result of the BMW EfficientDynamics development strategy, which can be found in almost every aspect of the new model. The car’s lightweight construction and aerodynamic features – headlined by the groundbreaking Air Curtains and Air Breathers – also help to maximize efficiency. At its core, the new BMW 4 Series Convertible has been engineered for performance excellence, while other features including Auto Start-Stop and on-demand operation of ancillary units help lower fuel consumption and emissions as well. Use of ECO PRO mode gives the potential to cut fuel use by as much as 20 percent.
The new BMW 4 Series Convertible uses a combination of driver assistance systems and mobility services (available as standard or optional under the BMW ConnectedDrive banner) to increase safety, comfort and convenience of access to infotainment features. Among the optional highlights are a new generation of BMW Navigation System, which offers extra capability, sharper graphics and 3D elements for the map display, the full-color BMW Head-Up Display; Active Driving Assistant, which warns the driver of a potential collision with a pedestrian, the intelligent; LED High Beam Assistant and the latest iteration of BMW Active Cruise Control with Stop & Go. As far as infotainment is concerned, efficient interface technology enables the integration of smartphones and numerous Bluetooth office functions. The latter also offers the driver the option of a dictation function with full speech recognition. Each feature has been carefully integrated to minimize driver distraction while the vehicle is in motion.
The new BMW 4 Series Convertible represents the fifth generation in the heritage of modern BMW convertibles. Just like the BMW 4 Series Coupe, the new BMW 4 Series Convertible introduces new dimensions of aesthetic design and sportiness. At the same time, the new model reinforces the company’s claim to years of market leadership when it comes to designing and building premium convertibles for the mid-size segment. More than ever before, it is the design language of the BMW 4 Series Convertible that accounts for its eye-catching and powerful presence on the road. The synergy of dynamic performance with maximum driving pleasure is another milestone in the story begun by the BMW 4 Series Coupe and now being continued with the launch of the BMW 4 Series Convertible. Athletic elegance, impeccable proportions.
The proportions of the new BMW 4 Series Convertible differ significantly from those of the outgoing BMW 3 Series Convertible. Although only an inch (26 mm) has been added to the car’s length (182.6 in / 4,638 mm), a 2-inch (50-mm) longer wheelbase (110.6 in / 2,810 mm) enhances the stretched Convertible’s profile. These dimensions combined with the BMW 4 Series Convertible’s characteristically short overhangs, long hood and set-back passenger compartment produce a visually balanced silhouette. The athletic appearance of the BMW 4 Series Convertible is particularly emphasized by its 1.7inch (43-mm) increase in the width (71.9 in / 1,825 mm). Notably, the rear wheel arches mark the car’s broadest point, giving a more aggressive stance. As a result, 1.8-inch-(45-mm) wider front track (60.8 in / 1,545 mm) and full 3.1 inches (81 mm) of extra width at the rear axle (62.7 in / 1,593 mm) promise – even at a standstill –further improvements in sporty characteristics for which BMW is known.
Signature BMW front-end design features, such as the double-kidney grille and four round headlights, undoubtedly identify the 4 Series Convertible as a BMW. It is unmistakably the 3 Series’ sibling, although the differences are apparent. The optional eye-catching full-LED headlights, with their hexagonal design, and the slightly forward-slanting BMW kidney grille form a single unit and strengthen the athletic presence of the BMW 4 Series Convertible on the road. Below the headlight line, the BMW 4 Series Convertible features a large air intake in the front apron. On the far left and right-hand edges of the air intakes are the additional small vertical apertures for the Air Curtains. These vents improve the airflow around the outside of the front wheels and help cut fuel consumption at higher speeds.
Powerfully taut surfaces and precise, sweeping lines define the athletic outline of the BMW 4 Series Convertible. The sloping roofline stretches the car’s overall appearance and elegantly accentuates the sporting profile of the flanks. The molding at the juncture of the three-piece folding hardtop and the body is an eye-catching touch. It is available in chrome, black or brushed aluminum, depending on the model variant. Additionally, the shallow, homogeneous side window graphic with the signature BMW Hofmeister kink at the trailing edge of the C-pillar generates dynamic visual tension. Below the windows, the double swage line inherited from the BMW 3 Series teams up with the striking door sill line to strengthen the body’s dynamic wedge shape. The car exudes dynamic elegance when the top is down, and the smooth, flowing look of the silhouette is in no way compromised by radio antennas or the roll bars, which are intelligently hidden behind the rear head restraints. Located just rearwards of the BMW 4 Series Convertible’s front wheels are Air Breathers designed to reduce drag around the wheel arches. Together, the Air Breathers and Air Curtains underline the sporting character of the car’s design and provide tangible evidence of the innovative aerodynamic solutions devised by BMW as part of the company’s EfficientDynamics development strategy. The sporting character of the BMW 4 Series Convertible extends into the powerful design of the rear. The prominent horizontal lines and broadly stretched L-shaped tail lights positioned at the outer edges of the rear draw extra attention to the muscular wheel arches and wide track.
The BMW 4 Series Convertible offers outstanding everyday driving qualities and a dynamic design, with the top up or down. These seemingly contradictory qualities were already combined in the BMW 3 Series Convertible, the predecessor model that set standards for premium mid-size convertibles. The hardtop of the BMW 4 Series Convertible features a number of design improvements that reduce noise levels for a much quieter interior ambience. The sound-absorbing headliner also reduces wind noise by up to 2 dB in comparison to the predecessor model.
All it takes is the push of a button to transform a dynamic coupe into an elegant, athletic convertible in a mere 20 seconds. The top can also be lowered when the vehicle is travelling at speeds of up to 18 km/h (approx. 11 mph). The vehicle’s air resistance with the steel top up is Cd 0.28 – and it is just Cd 0.33 when the hardtop is retracted. The redesigned windblock is standard in the US. The available three-temperature neck warmers allow for comfortable open-air driving at high speeds and low temperatures. The windblock is now smaller, lighter and easier to use, plus it is more effective than previous variants. When it is not needed, the windblock can be stored behind the rear seat to save space, which is also a new feature. The BMW 4 Series Convertible also has plenty of space in the trunk, even when the retractable hardtop is lowered. The new convertible offers wider access to the luggage compartment, and an electro-hydraulic loading assistance system raises and positions the folded hardtop in the trunk as needed to ensure maximum utilization of the 7.8 cu. ft. (220 liters) of storage space available.
The loading assistance feature makes sure that there is always ample access to the boot whether the top is up or down. Two storage compartments on the right and left of the main luggage area are also available for stowing small items when the retractable top is up.
When the top is up, the luggage compartment has a volume of 13.0 cu. ft. (370 liters) – that is 0.7 cu. ft. (20 liters) more than available in the BMW 3 Series Convertible. All trunk volumes are based on ECE measures. Even bulky items can be transported with the BMW 4 Series Convertible. A flat and level storage area can be utilized when the backrest of the rear bench seat is folded down. The load-through feature, which is standard in the US, makes even more space available: Either a wide opening between the rear passenger compartment and the trunk, or a smaller opening, for skis for example, when four people are seated in the vehicle.
The sporty character of the BMW 4 Series Convertible extends into the design of the rear. The horizontal lines and stretched tail lights positioned at the outer edges of the rear draw attention to the flared wheel arches and wide track. The sloping rear window has a lowering effect on the car’s tail and gives the body an even more aggressive look, and also shows off the car’s shoulders. The L-shaped taillights of the BMW 4 Series Convertible flow into the car’s overall design. They continue the path of the swage line from the flanks, creating a link to the rear end.
The interior of the BMW 4 Series Convertible blends sporting intent and exclusivity to stylish effect. An approach known as layering – the clever utilization of space through the structuring of lines and surfaces into layers – provides a natural canvas for the hallmark BMW driver focus, but is careful not to exclude the front passenger from the action. All of the controls are arranged ergonomically around the driver to provide optimum access to all functions. A sports steering wheel, crystal-clear circular instruments in black panel look and the freestanding, flatscreen iDrive monitor, the iDrive Touch Controller – all within easy reach on the center console – underline the sense of functional elegance. The dynamic horizontal lines of the instrument panel extend into the optional two-tone door and side panel trim. This is enhanced by the retractable hardtop cover to create an exclusive “boat deck” look. The interior design wraps around the driver and front passenger in an unbroken sweep and lends the interior an engagingly dynamic feel while showcasing the typically long doors. The interplay of surfaces and lines in the car’s side panels, plus the continuation of the accent strip, creates a visual connection between the front and rear of the interior.
The completely new design of the electrically adjustable front seats in the new BMW 4 Series Convertible includes integrated retractable seat belts – a feature not available on any other vehicle in this class. If desired, the standard seats and the sport seats, included with the Sport Line and M Sport, can be equipped with neck warmers for the driver and front passenger as part of the Cold Weather Package in the US. The dynamic character of the 4 Series Convertible can also be seen in the rear compartment. The bench design is contoured to form two individual seats, with cup holders and a storage tray for small items between them. The rear head restraints are separated from the concealed roll bars and can be removed if desired. The roll bars are comprised of two massive steel elements hidden behind the rear seats – in critical situations, sensors trigger the system and the roll bars are extended in less than 200 ms. Sport and Luxury Lines as well as M Sport available for personalization.
High-class material combinations, exclusive colors and opportunities for personalization define the premium feel inside the new BMW 4 Series Convertible. As well as the basic trim level, whose material and color concept accentuates the car’s classic character; customers have a choice of two BMW Lines as well as the popular M Sport to add individual touches to the car’s exterior and interior. The Sport Line and Luxury Line embody different takes on the car’s character, adapting the design and color scheme for the kidney grille and air intakes, exterior mirror caps, Air Breathers, trim strips in the front and rear apron, door sill strips and range of wheel rims to set the car apart externally from the basic trim level.
Sport Line: The Sport Line adds extra depth to the BMW 4 Series Convertible with a selection of exterior body features in high-gloss black. A sport suspension is included for rear-wheel drive models, setting an exciting tone for the driving experience. The standard high-gloss black B-pillars and black wrap-around window strip give the car an even sportier look, along with nine molded high-gloss black kidney grille slats in a chrome-colored surround. The three black air intakes in the front apron and the likewise black Air Breathers draw the eye to the car’s aerodynamic features. 18-inch or optional 19-inch light-alloy wheels (435i only) in twin-spoke design provide a more performance-oriented look. From the rear, the BMW 4 Series Convertible with Sport Line can be identified by the black trim strip level with the rear apron and the black exhaust tips. Inside the car, black and red accents, such as the red trim rings in the inner circle of the instrument dials and red stitching on the sport steering wheel, provide a pronounced contrast. Sports seats are included. The available Coral Red interior includes Coral Red leather sport seats, red door panel trim and a red lower section for the instrument panel.
Luxury Line: High-gloss chrome touches give the exterior of the BMW 4 Series Convertible a particularly elegant and exclusive appeal. 11 kidney grille slats with chromed fronts and matte black sides, two high-gloss double bridges in the front apron’s outer air intakes and chromed Air Breathers all offer elegant touches. The chrome window surround is another visual highlight, with special 18-inch or optional 19-inch light-alloy wheels (435i only) available. The BMW 4 Series Convertible Luxury Line is recognized from the rear by a high-gloss chrome strip in the rear apron and the chrome exhaust tips. The interior also stands out with various chrome elements, such as the surround for the audio and air conditioning system. High-gloss wood strips, leather seats with stitching and a choice of two upholstery variants in four colors highlight the possibilities in the Luxury Line. Exclusively available for the BMW 4 Series, Ash Grain anthracite fine wood trim surfaces and a Pearl Gloss Chrome metal inlay round off the Luxury Line features.
M Sport: Customers wishing to endow their new BMW 4 Series Convertible with as much of the traditional Ultimate Driving Machine character as possible may opt for M Sport. It includes an M aerodynamic package including numerous body components (front apron with large air intakes, rear bumper with diffuser, side skirts) and high-gloss Shadow Line trim. The exterior paint shade Estoril Blue Metallic is available only with M Sport on the 4 Series Convertible. M Sport is further distinguished by 18-inch or optional 19-inch light-alloy wheels (435i only) in M design. Inside, features such as M door sill finishers, an M leather steering wheel and an M driver’s footrest complete the atmosphere. Technical features of this package include M Sport suspension (rear-wheel drive models only) and M Sport Brakes (also a stand-alone option on all 435i Convertibles and an optional upgrade on 428i Convertible when M Sport is chosen) which includes calipers painted in blue finish.
The new BMW 4 Series Convertible benefits from BMW’s customary approach of splitting steering and drive forces between the front and rear axles, which is the ideal platform for balanced driving characteristics, directional stability and agile handling. It also has a 50:50 weight distribution, which sets it apart from its competitors. Taking into account its low center of gravity, unique chassis set-up and lightweight construction, the 4 Series Convertible is an exceptionally dynamic overall package which will satisfy every type of driver.
The chassis construction of the new BMW 4 Series Convertible is based on that of the new BMW 4 Series Coupe. However, the springs and damping, axle kinematics and elastokinematics have all been tailored precisely to the character of the new convertible. Indeed, the chassis engineers have managed to make further improvements to the agility and accuracy offered by the chassis, thanks to modification and fine-tuning of variables such as the camber angle, the track and the roll center. Last but not least, special body strengthening elements in the front section and the undercarriage of the car help to further enhance steering precision and feedback.
The front suspension of the new BMW 4 Series Convertible combines maximum stiffness with minimum weight. Aluminum torque struts, wishbones and swivel bearings bring a reduction in unsprung weight. At the same time, the engineers optimized the kinematics of the double-pivot suspension for agility and precision. Adjusting the position of the control arms in the swivel bearings from their arrangement on the latest BMW 3 Series Sedan gives the car a .7-inch (19-mm) lower roll center, which has a positive effect on driving performance. An additional strut between the front axle subframe and body sill creates a stiffer overall connection between the front wheels and the car’s main structure, so the transverse forces generated on entry into corners are transferred to the car more directly. The BMW 4 Series Convertible responds more directly to the driver’s steering commands and displays more sporty characteristics and greater agility. And that means it carves through corners with ease and precision.
The rear axle of the new BMW 4 Series Convertible is a key component in its driving characteristics, but that does not mean comfort has been overlooked. This construction is based on the five-link concept, and its elastokinematics have been tuned specially for this sporting convertible. In addition, extra-wide mounts and supports on the wheel carriers for track and camber, slightly repositioned pivot points, stiff control arms and suspension subframes, and the use of thrust arms to connect the suspension with the body all provide an excellent basis for a sporty and dynamic overall set-up. The result is precise and assured wheel location, directional stability in any driving situation. Aerodynamic features around the rear suspension also contribute to driving precision.
A standard feature of the new BMW 4 Series Convertible is the Servotronic system which provides speed-sensitive power assistance. The system’s precise programming results in sharper steering feel, feedback, precision, accuracy and immediate response. The new BMW 4 Series Convertible can also be equipped with Variable Sport steering as part of the optional Dynamic Handling Package. This provides a somewhat “quicker” on-center steering ratio which then varies depending on the amount of steering “lock” (angle) applied by the driver. The result is even more-lively steering during the “turn-in” phase of cornering, and excellent stability mid-corner and on corner exit.
The new BMW 4 Series Convertible comes equipped with powerful swing-caliper or fixed-caliper brakes and large, inner-vented brake discs. The calipers on the front brakes are made of aluminum. As well as low unsprung weight, the brakes also stand out with their high heat tolerance, excellent wet braking performance, ease of use and excellent feel. A brake pad wear indicator and the Brake Drying function are standard on all models.
Dynamic performance and handling is significantly influenced by vehicle weight. The new BMW 4 Series Convertible’s intelligent lightweight construction concept makes a major contribution to the car’s dynamic qualities. The use of high- and ultra-high-strength multi-phase steels and tailored blanks, customized precision components for specific applications, maximizes the body’s strength. The torsional rigidity has been increased by 40 percent compared with its predecessor. The top also plays a decisive role in a convertible, because the car does not have a roof serving as a permanent support element. The BMW 4 Series Convertible is up to 44 lbs. (20 kg) lighter than its predecessor, depending on the model, even though the new vehicle is larger and complies with more stringent safety standards.
When the hardtop is up, the new BMW 4 Series Convertible highlights its aerodynamic qualities with a Cd (drag coefficient) of 0.28 – which is the same figure as for the new BMW 4 Series Coupe. The convertible achieves a Cd of 0.33 when the top is down. This is possible due to the optimization of the front apron and the rear of the car. The BMW Air Curtains in the front apron generate a veil of air which reduces turbulence – and therefore drag – around the front wheels. The new Air Breathers positioned rearwards of the front wheel arches divert some of the air flowing through the wheel arches, thereby reducing air resistance. These innovations serve to optimize fuel efficiency and – at the same time – enhance the lift coefficient.
The M Sport suspension included is part of the Sport Line and M Sport. It works with a firmer spring/shock absorber set-up and stiffer anti-roll bars, and its kinematics/ elastokinematics (bushings and bearings) have also been tweaked to suit the new BMW 4 Series Convertible. The M Sport suspension also includes 18-inch or optional (435i only) 19-inch light-alloy wheels. Alternatively, customers can select a lowered (non-xDrive models) Adaptive suspension, included in the Dynamic Handling Package, which adjusts the electronic damper mapping to each road surface and driving situation. The driver can also use the Driving Experience Control switch to vary the basic suspension settings between comfort and sport, according to personal preference. For performance-minded customers, BMW offers the M Sport Brakes. The aluminum fixed calipers (four-piston at the front, two-piston at the rear) and large discs combine low weight with short stopping distances.
The new BMW 4 Series Convertible also offers drivers the ability to change between sporty, eco or comfort settings, depending on mood or preference. Using the Driving Experience Control switch with ECO PRO mode on the center console, drivers can select between ECO PRO, COMFORT, SPORT or SPORT+ (most models). Each of these selections will activate different settings for the powertrain and suspension components.
In SPORT mode, throttle response is improved and the steering becomes more direct. If the automatic transmission is fitted, the gearshift points are also altered for sportier driving. Depending on the car’s specification, different settings can be selected for the powertrain and chassis components. In SPORT+ mode, the Dynamic Stability Control thresholds are raised and Dynamic Traction Control (DTC) is activated. The electronic limited-slip function for the rear differential can then provide better acceleration out of corners or sharp bends.
Owning a Convertible reflects a driver’s passion for elegant lines and top-down motoring, but it does not rule out performance driving and high-class dynamics. The state-of-the-art powertrain technology under the skin of the new BMW 4 Series Convertible ensures it delivers an engaging driving experience that satisfies even the most demanding expectations.
Longitudinally front-mounted, inline engines powering the rear wheels continue BMW’s tradition in creating a drive concept that delivers great driving pleasure. Both engines available for the new BMW 4 Series Convertible use BMW TwinPower Turbo technology, which combines sporty performance characteristics with improved efficiency. Available from launch are an inline six-cylinder engine for the BMW 435i Convertible and a four-cylinder unit for the BMW 428i Convertible. These award-winning engines not only supply the BMW 4 Series Convertible with outstanding acceleration and elasticity, they also keep the cars weight down to improve driving dynamics and lower fuel consumption.
The new BMW 435i Convertible gives full value to performance-minded drivers thanks to a refined high-revving inline-six engine with instant power delivery and great fuel efficiency. Equipped with High Precision Direct Injection and Valvetronic fully variable valve control, the 3.0-liter engine with aluminum crankcase develops maximum output of 300 hp between 5,800 and 6,000 rpm. Peak torque of 300 lb-ft is generated at 1,200 rpm and remains on tap up to 5,000 rpm. The multi-award winning six-cylinder engine allows the new BMW 435i Convertible to accelerate from 0-60 in about five-and-a-half seconds, on the way to an electronically limited 250 km/h (155 mph) top speed, when equipped with performance tires.
Smooth power delivery, available torque, high revs and low weight define the 2.0-liter four-cylinder turbocharged engine. BMW’s engine technology package – including High Precision Direct Injection, twin-scroll turbocharging, Double-VANOS variable camshaft control and Valvetronic throttle-less intake technology – offers high performance potential combined with low fuel consumption and emissions.
The cutting-edge four-cylinder engine of the new BMW 428i Convertible generates maximum output of 240 hp at 5,000 – 6,500 rpm and peak torque of 255 lb-ft, which the driver can access between 1,250 and 4,800 rpm. This allows the 428i to sprint from 0 to 60 in about 6.2 seconds and has an electronically limited top speed of 250 km/h (155 mph), when equipped with summer performance tires. The engine gives a smooth power delivery from the moment it spins above idle to the upper regions of its engine speed range along an almost linear curve.
The standard high-performance 8-speed Sport automatic transmission – with its extra gears, quick gear changes and delightful shift comfort – is perfectly matched to the character of the new BMW 4 Series Convertible. With only small changes in rpm between gear ratios, the ideal gear is on hand in virtually any situation out on the road. Many technical features and internal efficiencies ensure powerful acceleration and short bursts of speed are possible with no additional fuel consumption. The 8-speed automatic’s intelligent control technology enables quick shift and reaction times and direct downshift capability. Drivers may also shift gears using paddles on the steering wheel. Drivers can choose between Normal and Sport transmission modes using the gear shift lever or the Driving Experience Control switch.
As an alternative to rear-wheel drive, the 428i Convertible can also be specified with BMW xDrive intelligent all-wheel drive. As well as sharing all the traditional virtues of all-wheel-drive systems – such as increased traction, safety and the optimum transfer of engine power to the road – BMW xDrive can also reduce oversteer or understeer that may occur in cornering situations. In the process, it enhances agility and precision, e.g. when turning into corners or when accelerating strongly out of them.
The new BMW 4 Series Convertible comes with the Auto Start Stop function. Another standard feature is Brake Energy Regeneration, which ensures that – as far as possible – power for the vehicle’s electrical system is generated during braking and coasting. ECO PRO mode is effective in helping the BMW 4 Series Convertible driver maintain an efficient and economical driving style. As well as tweaking the accelerator’s responses and the engine management system, ECO PRO also benefits from intelligent energy and climate management. The system gives the driver tips and ideas – relevant to the driving situation at hand – on how to reduce fuel consumption even further through adjustments in personal driving style. Average fuel consumption can be cut by up to 20 percent in ECO PRO mode, with a corresponding boost to the car’s range on a tank of fuel.
The new BMW 4 Series Convertible’s ancillary components also play a role in the car’s intelligent energy management. Examples include the on-demand coolant pump, the map-controlled oil pump and the Electric Power Steering system, which only consumes electricity when steering assistance is actually required. The special air conditioning compressor works on the same principle. As soon as the driver switches the air conditioning off, the belt drive to the compressor is disconnected to minimize power drain.
The use of lightweight materials makes a significant contribution to efficiency and agility, and helps to give BMW cars their impressive dynamic capability. Weight savings can be found in every area of the development process. As well as the use of plastics and cutting-edge composite materials, the increased deployment of aluminum components in the engine and chassis construction has also reduced the weight of the corresponding assemblies.
BMW Assist will be standard on the new 4 Series Convertible. It will include 10 years of eCall emergency calling and enhanced Automatic Collision Notification as well as BMW Teleservice. BMW Assist eCall includes enhanced Automatic Collision Notification, which includes the groundbreaking Urgency Algorithm, developed in cooperation with the William Lehman Injury Research Center in Miami. In addition to the vehicle’s exact position and direction of travel, details of the vehicle model and all the data gathered by the sensors in the car are relayed to the call center as well. This information provides indications as to the nature and severity of the collision, while the deployment of the car’s restraint systems gives an idea of the number of people injured and allows frontal, rear, side or even multiple collisions to be identified and differentiated. The Urgency Algorithm transmits the likelihood of severe injury. On the basis of all accident-related data, the call center decides which and how many emergency services are required at the accident site (e.g. doctor, paramedic, fire brigade, helicopter). The data also enables the first responders to alert the appropriate medical care for those involved in the accident before they have even arrived at the scene. The call center will also stay in contact with the vehicle’s occupants until the emergency services arrive, speaking to them in their native language where possible. As well as automatic activation, the system also allows the driver or front passenger to trigger the emergency call manually in order to help other road users in distress by alerting the call center.
TeleService tells the driver if and when maintenance is required. Fixed service intervals become a thing of the past, because the intelligent maintenance system, Condition Based Service, constantly monitors your vehicle's service needs. When necessary, the vehicle communicates service-relevant data to the nearest BMW Service Center by making an Automatic BMW TeleService Call.
BMW’s groundbreaking user interface has undergone constant improvement and development since its inception in 2002. On the heels of its most recent update, BMW’s iDrive will see significant enhancements for model year 2014. Not only will more models receive the latest iDrive 4.2, but the system gets enhancements that improve the user experience in the areas of navigation, Advanced Real Time Traffic Information, connectivity, entertainment, online access and voice commands. One example is the ability to engage automatic time setting. When active, the time will automatically be adjusted for Daylight Saving or Standard time as well as changes in time zone while traveling.
The latest BMW navigation system, which is optional on the new BMW 4 Series Convertible, has received many enhancements. Before setting out, the prescribed route can be tailored to avoid certain areas, for example, if the user anticipates heavy traffic or knows of construction on that route. The system will recalculate the route to avoid the selected area. Multiple areas to avoid can be selected for a given route and the size of coverage is fully adjustable. The online Google search function has been enhanced for customers who subscribe to BMW Online. Users can now search for points-of-interest (POI) via voice. Once the user has spoken their POI, the navigation system can then guide the driver to their desired destination.
Advanced Real Time Traffic Information was significantly enhanced for iDrive 4.2 to provide a clearer view of traffic congestion using green, yellow and red indicators along the route to indicate the degree to which roads are clear or congested. The traffic incident view has been enhanced again to provide more precise indications in red of the specific location of stopped traffic.
When equipped with the BMW navigation system, the new 4 Series Convertible will include the new iDrive controller with Touchpad. The touchpad is integrated into the top of the controller and does not require a separate location. Phone numbers, contact names and address can be written out directly on the touchpad. The user can seamlessly switch between the touchpad and the controller while information is being entered. The touchpad can also be used to zoom in and out on the interactive map.
One of the highlights of the new BMW 4 Series Convertible is the available full-color Head-Up Display. HUD projects key information onto the windshield to appear directly in the driver’s field of view to minimize the time the driver has to look away from the road. Depending on the vehicle specification, not only is the current speed displayed, but speed limits and passing restrictions are also flashed up for the driver’s benefit, along with navigation instructions and various warning messages. The variety of driver assistance systems available for the new BMW 4 Series Convertible brings the amount of information that can be shown in the Head-Up Display to a whole new level. The intensity of the projections adapts automatically to the light conditions and follows the illumination of the cockpit dials. The positioning of the projections on the windscreen can also be adjusted using the iDrive Controller.
A camera fitted to the rear-view mirror scans in front of the vehicle and uses image processing to detect any people or vehicles within its field of vision. When it recognizes a risk of collision with the vehicle in front, the system produces an audible warning and a visual signal appears in the instrument cluster or the optional Head-Up Display (if specified) to alert the driver. Should a collision be unavoidable, automatic moderate hazard braking is actuated. During urban journeys in sufficient light conditions, if the system detects a potential collision with a pedestrian, it warns the driver and, if necessary, triggers automatic hazard braking. In both cases – in addition to the warnings – the vehicle’s brakes are automatically primed for emergency braking and the activation thresholds of the Brake Assist system are lowered. The Lane Departure Warning system is also a part of the Driving Assistant option.
The latest development stage of the familiar Active Cruise Control with Stop & Go function (ACC Stop & Go) uses a front-mounted camera on the rear-view mirror in addition to the full-range radar sensors to provide an enhanced interpretation of the traffic situation ahead. When driving in slow-moving traffic or traffic jams, the driver is able to safely move along with the flow of traffic and let the vehicle’s automatic systems handle the tasks of stopping, pulling away again and approaching junctions where there are already vehicles waiting ahead. Combining radar and video data in this way improves detection of other vehicles and reduces the system’s reaction time. If a vehicle ahead brakes very sharply in free-flowing traffic, requiring the driver to take action, he or she is prompted to do so by a two-stage warning. Active Cruise Control with automatic distance control is now available at speeds between 20 and 130 mph (30 km/h and 210 km/h). The intelligent cruise control function remains active at speeds above 130 mph (210 km/h).
Among the convenience and safety-enhancing assistance systems on offer are Active Blind Sport Detection and Lane Departure Warning, with the latter available as part of the Active Driving Assistant option. These systems use radar sensors and camera monitoring to alert drivers to potential collision risks when changing lanes or if they veer out of lane unintentionally. It also issues a warning when driving too close to the vehicle ahead.
The BMW 4 Series Convertible is available with the option of full-LED headlights, which provide a further safety boost when driving at night. The optional High Beam Assistant in conjunction with full-LED headlights ensures that the driver can enjoy optimal visibility at all times without having to switch manually between high and low beam. The High Beam Assistant adapts to the traffic situation by switching to low beam on one or both sides.
In addition to the rear view camera and Park Distance Control, customers are also able to get the Surround View function with Side View and Top View, which provides a bird’s-eye view of the BMW 4 Series Convertible and the area around it. It enables the driver to carry out precise maneuvers in tight spaces. If the car is moving at a speed under 12 mph (20 km/h), the Side View function can additionally be activated to allow the driver to keep an eye on cross-traffic. Another convenience system is the Parking Assistant system, which is able to maneuver the car into parking spaces parallel to the direction of travel. All the driver has to do is operate the accelerator and brake pedal while the Parking Assistant takes care of the steering.
The new 4 Series Convertible is a technical tour-de-force which is, at its heart a true BMW. The 2014 428i Convertible and 435i Convertible will arrive in US showrooms in the first quarter of 2014.