About a month ago we brought you some ‘official brochure images’ of the BMW 4 Series Convertible which has now had its public debut at the 2013 Los Angeles Auto Show.

Refined engine options

According BMW, the U.S.-spec model will be available in a 428i variant equipped with a 2.0-litre 4-cylinder turbo engine which produces 179kW of power and 345Nm of torque. The 435i model is fitted with a beefier 3.0-litre inline-six engine delivering 224kW and 406Nm of torque.

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.

Both engines 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.

For other countries such as Europe, BMW will also offer a 4-cylinder 2.0-litre turbodiesel unit delivering 135kW, and accelerating from 0-100 km/h in 6.2 seconds.

Improved design and functionality

TheBMW 4 Series Convertible is visibly larger in width and wheelbase than the outgoing 3 Series Convertible. It also features a three-piece retractable hardtop which needs 20 seconds to open and close, and has been further enhanced with advanced soundproofing and noise-absorbing headliner. The sound-absorbing headliner also reduces wind noise by up to 2 dB in comparison to its predecessor.

In addition, the convertible still boasts some of the traditional styling like the BMW-typical short overhangs, long hood, a set-back passenger compartment with flowing roofline, and the rear wheel arches which give the car a more aggressive stance. New elements include the Air Breathers positioned rearwards of the front wheel arches to reduce drag.

The cargo area has increased by 20 litres to 370 litres when the top is up and when folded down the capacity drops to 220 litres which should suffice for short journeys.

The interior of the BMW Series 4 Convertible presents a stylish fusion of sporty allure, elegance and exclusivity. It features new adjustable seats with integrated seatbelts, a two-tone effect for the door and side panels, a sports steering wheel, crystal-clear circular instruments in black panel look and the freestanding, flat screen iDrive monitor, the iDrive Touch Controller, and a retractable hardtop cover to create an exclusive “boat deck” look.

As with the Coupe, standard kit in theBMW 4 Series Convertible will include xenon headlights (with full LED lights available as an option), heated electric front seats and front and rear parking sensors on all models.

TheBMW 4 Series Convertible is also divided into the same trim lines as its siblings. The Sport Line models will feature 18- or 19-inch alloy wheel designs and sportier appearance tweaks. The Luxury Line trim will also include unique wheel design, matte black and high gloss touches inside and out, while the M Sport version adds the M Aerodynamic package (front bumper, rear bumper, diffuser, and side skirts) plus a unique set of wheels and M-branded details inside and out.

The BMW 4 Series Convertible models 428i and 435i are expected to arrive in showrooms in 2014.

BMW 4 Series Convertible gallery