BMW 4 Series Convertible

With the new 4 Series Convertible BMW has completed the new 4 Series range, that replaces the coupe and convertible variants of the 3 Series.

The design of the open-top 4 Series is directly derived from the Coupe, revealed back in June, and compared to the previous 3 Series Coupe features increased dimensions and a sportier character.

As its coupe counterpart, the new 4 Series Convertible is characterized by the typical proportions of BMW sporty models, with the long hood, a minimal front overhang and a set-back cabin.

The three-piece retractable hardtop features an advanced soundproofing system with a noise-absorbing headliner.

When closed, it has a clean look – without the B pillars – and compared to the stretched rear section of the coupe, gives the Convertible a distinctive three-box appearance.

The wrap-around interior featured new seats with integrated seatbelts.

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 contribute in combination with the hardtop cover to the “boat deck” look.

At model launch the BMW 4 Series Convertible will be offered with a choice of three engines: an in-line six-cylinder gasoline unit (BMW 435i Convertible), a four-cylinder gasoline engine (BMW 428i Convertible) and a four-cylinder diesel (BMW 420d Convertible).

These engines have an output range from 135 kW/184 hp to 225 kW/306 hp and are coupled with a six-speed manual gearbox as standard – BMW also offers an optional eight-speed automatic transmission or an eight-speed Sports automatic transmission.

Below we report the official design details. Also check the gallery of sketches.

From the official Press Release:

Exterior Design

The overall length of 4638 millimetres has been extended by 26 mm, the wheelbase has grown by 50 mm and, together with the 43 mm added to the front track (1825 millimetres), this rounds off the athletic yet elegant appearance of the vehicle. The shorter overhangs in comparison with the BMW 3 Series Convertible, the long bonnet, the set-back passenger compartment and the wider track (+ 45 mm front, + 81 mm rear) further accent the silhouette.

Although the BMW 4 Series Convertible expresses more dynamic conviction and sportiness than its predecessor, the design of the front end reflects its close family ties with the BMW 3 Series. The kidney grille and twin headlights are characteristic design elements that are unmistakably BMW. The car’s head-turning front end is a demonstration of precise contours and multifaceted surfaces. The optional adaptive full-LED twin headlights, with their hexagonal design, team up with the slightly forward-slanting
BMW kidney grille to form a single stylistic unit and strengthen the athletic appearance of the BMW 4 Series Convertible on the road. The width of the vehicle is accentuated by a large air intake in the front apron below the headlight line. On the far left and right-hand edges of the air intake are the additional, aerodynamically refined small vertical apertures for the Air Curtains.

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 moulding at the juncture of the three-piece folding hardtop and the body is an eye-catching touch. It is available in chrome, black or satinated aluminium, 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-over 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 its BMW 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 height of the BMW 4 Series Convertible is 1384 mm, making it a mere 7 mm taller than the BMW 4 Series Coupe.
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 a push of a button to transform the dynamic coupe into an elegant athletic convertible within 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 optional windblock, which is now wider at the sides, and the 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 boot, even when the retractable hardtop is lowered: Unlike earlier models, the new convertible offers wider access to the luggage compartment, and an electro- hydraulic loading assistance system pivots and positions the folded hardtop in the boot as needed to ensure maximum utilisation of the 220 litres 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.

But that is not all: 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 closed. When the top is up, the luggage compartment has a volume of 370 litres – that is 20 litres more than available in the BMW 3 Series Convertible.

Even bulky items can be transported with the BMW 4 Series Convertible. A flat and level storage area can be utilised when the backrest of the rear bench seat is folded down. If the car is equipped with the optional load-through feature, even more space is available: Either a wide opening between the rear passenger compartment and the boot, or a smaller opening, for example for skis, when four people are seated in the vehicle.

(Source: BMW)