Review: BMW F33 4-Series Convertible (2014-17)

Overview

Released in Australia in March 2014, the BMW F33 4-Series Convertible was a two-door, four-seat convertible with a retracting metal roof. Manufactured in Regensburg, Germany, the rear-wheel drive F33 4-Series range consisted of the 420d, 420i, 428i and 435i models (see table below). All models, however, were be fitted with BMW’s EfficientDynamics fuel-saving technologies such as Auto Start Stop (engine shutdown when stationary), an ECO PRO driving mode, a coasting mode which disengaged the powertrain to prevent engine braking and on-demand operation of ancillaries such as electric power steering.

In May 2016, the BMW F33 4-Series Convertible range was revised as the 428i and 435i replaced by 430i and 440i, respectively. Furthermore, fuel efficiency was improved for the petrol engines and safety equipment was enhanced as BMW’s ‘Driving Assistant’ was fitted as standard across the range.

BMW F33 4-Series Convertible specifications
	Engine	Years	Trans.	Peak power	Peak torque
420d	2.0-litre N47 D20 turbo-diesel I4	2014-15	6sp man., 8sp auto	135 kW at 4000 rpm	380 Nm at 1750-2750 rpm
420d	2.0-litre B47 D20 turbo-diesel I4	2015-17	6sp man., 8sp auto	140 kW at 4000 rpm	400 Nm at 1750-2500 rpm
420i	2.0-litre N20 B20 turbo petrol I4	2014-17	6sp man., 8sp auto	135 kW at 5000-6250 rpm	270 Nm at 1250-4500 rpm
428i	2.0-litre N20 B20 turbo petrol I4	2014-16	6sp man., 8sp auto	180 kW at 5000 rpm	350 Nm at 1250-4800 rpm
430i	2.0-litre N20 B20 turbo petrol I4	2016-17	6sp man., 8sp auto	185 kW at 5200 rpm	350 Nm at 1450-4800 rpm
435i	3.0-litre N55 B30 turbo petrol I6	2014-16	6sp man., 8sp auto	225 kW at 5800 rpm	400 Nm at 1200-5000 rpm
440i	3.0-litre B58B30 turbo petrol I6	2016-17	6sp man., 8sp auto	240 kW at 5500 rpm	450 Nm at 1380-5000 rpm

Dimensions and body

Compared to the E93 3-Series Convertible , the F33 4-Series Convertible was 26 mm longer (at 4638 mm), 43 mm wider (1825 mm), 11 mm lower (1384 mm) and had a 50 mm longer wheelbase (2810 mm). With its roof in position, the 4-Series Convertible had a drag coefficient of 0.28 Cd, though this increased to 0.33 Cd when the roof was lowered. Furthermore, torsional rigidity for the 4-Seres Convertible increased by 40 per cent through the use of high- and ultra-high strength multi-phase steels and tailored blanks.

The three-piece retractable hardtop could open in twenty (20) seconds and be operated at speeds of up to 18 km/h. Boot capacity for the 4-Series Convertible was 370 litres with the roof in place and 220 litres when lowered.

Suspension and steering

Like the related BMW F30 3-Series sedan and F32 4-Series Coupe , the 4-Series Convertible had a double-joint tie-bar front axle with spring struts and a five-link rear axle. For Australia, both the 428i and 435i models were fitted with BMW’s ‘Adaptive M’ suspension which lowered the ride height by 10 mm and used electronically-controlled dampers to adjust damper resistance according to the road surface and driver behaviour. From May 2016, however, Adaptive M suspension was fitted as standard for Australian-delivered vehicles.

The BMW F33 4-Series Convertible had rack-and-pinion steering with electric power assistance.

Safety equipment

Standard safety equipment for the BMW F33 4-Series Convertible included dual front airbags, front seat-mounted side airbags, ABS, brake assist, electronic brake force distribution, electronic stability control, traction control, corner brake control, front and rear seatbelt pretensioners, front seat load limiters and automatically deploying roll bars. In the event of a collision, ‘BMW Intelligent Emergency Call’ would automatically transmit vehicle information and call the BMW ConnectedDrive Call Centre for assistance; emergency services would then be informed by the call centre if required. A manual emergency call could also be initiated via the SOS button.

Like the F30 3-Series sedan and F32 4-Series Coupe , the 4-Series Convertible was fitted with BMW’s ‘Active Protection’ system which operated automatically at speeds above 18 km/h. If the front-mounted camera or radar detected an emergency braking manoeuvre or the onset of heavy understeer or oversteer, Active Protection prepared for a collision by retracting the front seatbelts and closing the side windows and sunroof. If a crash was unavoidable, the Active Protection system would autonomously apply the brakes. Following the initial impact, the system would also seek to bring the vehicle to rest with a maximum deceleration of 5 m/s²; while the brakes would lock for a further 1.5 seconds to reduce the likelihood of a second collision.

In May 2016, standard safety equipment for the BMW F33 4-Series Convertible was extended to include:

BMW’s ‘Driving Assistant’:
- Approach Control Warning: if the driver was rapidly approaching an obstacle ahead, the driver would receive a visual warning in the instrument cluster, followed by a warning tone. If the driver failed to respond, the brakes would be applied automatically with deceleration of up to 3 m/s²;
- Lane Departure Warning (LDW): operating at speeds above 70 km/h, a camera could scan the road up to 50 metres ahead and detect lane markings. If the driver unintentionally deviated from their lane, the driver would be alerted via steering wheel vibrations and a visual warning in the instrument cluster;
- Pedestrian Warning with Light Braking Function: used a camera to scan the road ahead when the vehicle was travelling at speeds between 10 km/h and 60 km/h. if a potential collision with a pedestrian was identified, the driver would receive a visual warning in the instrument cluster and an alert tone; simultaneously, the braking system would be primed for maximum response. If the driver failed to respond, medium-force braking would be automatically initiated – this would reduce the risk of collision and prompt the driver to react. Once the driver applied the brake pedal, maximum braking force would be applied; and,
Lane Change Warning: used two radar sensors in the rear of the vehicle to monitor traffic in adjacent lanes with a range of up to 60 metres behind the vehicle. The Lane Change Warning would warn the driver of potentially dangerous situations by conveying warnings through the instrument panel, an LED icon on the door mirror and steering wheel vibrations.

Models with the M Sport package (standard for the 430i, 435i and 440i) were also fitted with an upgraded braking package which included four-piston front brake calipers.

Features: 420d, 428i and 435i M Sport

Standard features for the BMW 420d Convertible included a six speaker sound system with auxiliary inputs (3.5 mm/USB) and Bluetooth connectivity, BMW’s ‘Professional’ navigation system with an 8.8-inch colour screen, 20Gb hard-drive and iDrive touch controller, dual-zone climate control air conditioning, Dakota leather upholstery, power adjustable and heated front seats with memory settings, bi-xenon headlights, automatic headlights, rain-sensing wipers, front and rear parking sensors, a rear view camera, through-loading rear seats, remote central locking, power windows and mirrors, a height and reach adjustable steering wheel, a trip computer and an immobiliser.

The BMW 428i Convertible was further equipped with a nine speaker HiFi sound system, power adjustable lumbar support for the front seats, and electrochromatic interior and door mirrors.

The BMW 435i Convertible was distinguished by its 500 watt harman/kardon surround sound system with twelve speakers, BMW’s ‘Air Collar’ (neck heating) and proximity key for keyless entry (BMW’s ‘Comfort Access’).

Sport Line, Modern Line, Luxury Line and M Sport package

Within the BMW F33 4-Series Convertible range, the 420d and 428i were available in Sport Line, Modern Line or Luxury Line trims as standard –

Luxury Line:
- Exterior highlights: chrome treatment for the front and rear bumper, kidney grille slats and exhaust tip, double bridges in the front apron’s outer air intakes, Air Breathers (positioned behind the front wheel arches), window recess covers and exhaust tip; and,
- Interior features: chrome surrounds for the centre stack, high-gloss wood strips, and upholstery colours of saddle brown, Veneto beige or black.
Sport Line:
- Exterior highlights: high-gloss black treatment for the kidney grille slats (in a chrome-coloured frame), front and rear bumper trims, B-pillar trim, window recess covers, Air Breathers and exhaust tip; and,
- Interior features: chrome pearl grey surrounds for the air conditioning and radio controls, a sport leather steering wheel with red contrast stitching, high-gloss black interior trim with coral red accent lines and the choice or black leather upholstery with red stitching or coral red upholstery with black stitching.
Modern Line:
- Exterior highlights: turbine style alloy wheels, matt chrome grille slats, satinated aluminium trims for the bumpers, window recess covers, Air Breathers and exhaust tip; and,
- Interior features: oyster or black Dakota leather upholstery, a light-coloured dashboard, dark oyster or black steering wheel and Pearl Gloss Chrome accent strips.

The 435i, however, was fitted with BMW’s ‘M Sport’ package as standard –

Exterior highlights: 19-inch ‘M’ double-spoke alloy wheels (with M Sport suspension), M aerodynamics package (including a larger front air intake, side skirts and rear diffuser), and high-gloss Shadow Line trim elements; and,
Interior features: contoured sports seats with M piping and blue contrast stitching, an M leather steering wheel, M door sill finishers and a ‘BMW Individual’ anthracite roof-liner.

May 2016 update

In May 2016, standard features for the BMW F33 4-Series Convertible were extended to include BMW’s ‘Adaptive M’ suspension, a head-up display (HUD), power folding door mirrors and BMW’s ‘Surround View’ camera system which included top and side views. Furthermore, the 430i Convertible was fitted with BMW’s ‘M Sport Package’ as standard.

2016 BMW F33 428i Convertible Individual

Released in Australia in January 2016, the BMW F33 428i Convertible Individual was specified with the following BMW Individual features:

Fine-wood trim in Piano Black;
Extended Merino leather upholstery in Opal White;
Champagne-Quartz paint finish; and,
Leather instrument panel.

Otherwise optional features that were fitted as standard for the BMW F33 428i Convertible Individual included 19-inch double-spoke M light alloy wheels in Orbit Grey, Harman/Kardon surround sound system, adaptive LED headlights, BMW’s Connected Drive Freedom, Innovations Package, M Sport package, Air Collar, internet connectivity and satinised aluminium exterior trim. Australian deliveries of the BMW F33 428i Convertible Individual were limited to twenty (20) vehicles.

Review: BMW F33 LCI 4-Series Convertible (2017-20)