Driven: BMW 4 Series Convertible open for business

BMW Australia has flagged it wants to attract more female buyers to the male-dominated brand, with its all-new 4 Series Convertible launched this week showing potential to do most of the heavy lifting.

BMW Group Australia product planning manager Christoph Priemel said the previous-generation 3 Series Convertible that the 4 Series replaces had one of the highest female buyer profiles in the brand – a factor the car-maker wants to accelerate with the new drop-top.

“Our marketing has identified as an aim, and after looking at it from a past perspective, that the convertible is one of the models that the female share is around 34 per cent of buyers,” Mr Priemel said.

“It’s quite an outstanding figure, because usually when you look at it from the perspective of 4 Series Coupe, for instance, they are predominantly male and attracting a very high proportion of male buyers.

“It’s kind of understandable when you look at the nature of the car.”

BMW’s X1 compact SUV and 1 Series coupe attract the most female buyers – almost half of the coupe’s sales are not to males – while the X3 SUV and convertible follow closely.

The new 4 Series Convertible has arrived in Australia bearing an even number at the start of its name that BMW is using to differentiate two-door models from the odd-numbered four- and five-door variants.

It includes some never-before-seen technology that helps remove some of the lack of practicality of open-top motoring, making the fifth-generation small drop-top its most lifestyle-friendly to date.

Compared with the 3 Series it replaces, the new roofless 4 Series is 26mm longer, adds 50mm to its wheelbase, but drops 9mm in height. BMW’s engineers have also focused on agility, with the 4 Series Convertible now 43mm wider than the model it replaces, and with 45mm added to the front track and 81mm at the rear.

No overall weight savings have been realised, the 1690kg-plus model range weighing around the same as the previous model as a result of much more underbody stiffening that increases torsional rigidity by a claimed 40 per cent. This offsets significant weight-saving measures introduced in other areas.

BMW has launched the 4 Series Convertible with a three-model single-turbo ‘TwinPower’ line-up, featuring an entry-level turbo-diesel 420d priced from $88,800 (plus on-road costs), a turbo-petrol 428i from $97,500 – both are four-cylinder units – and the turbocharged inline six-cylinder petrol 435i starting at $126,600.

All models sit on an aluminium double-sprung strut axle up front, while down the rear the 4 Series features a lightweight multilink system.

As with the previous generation, the 4 Series’ folding roof is metal compared with the 6 Series convertible’s cloth trim. According to Mr Priemel, BMW did discuss whether the timing was right to shift to a rag-top in the interests of saving weight, but it was deemed unnecessary.

The roof stows in 20 seconds – about four seconds faster than the previous model – and this time around drivers can open or stow it at speeds of up to 18km/h.

The roof, which has more sound deadening to reduce noise by two decibels, stows neatly into the boot using a mix of hydraulic and electric pistons. It also includes a special button on the bootlid that can raise the stowed unit in the boot by 40cm, opening up a bigger load-through space so that long items such as surfboards can fit in once the rear seatback is flipped forward.

A luggage space cover that must clip in place before the roof can be moved back into position ensures whatever is in the boot will not damage the roof once it returns to its original position.

A new U-shaped rollover bar running the width of the cabin that springs up from behind the rear seat bench helps to save 15kg over separate hoops, as well as adding torsional stiffness to the 4 Series. It also allows a big 670mm x 270mm gap to open up to the boot once the seatback flips forward.

Improvements to space have added another 20 litres to the boot, improving it to 370L when the roof is up, and an extra 10L when the roof is stowed, lifting it to 220L.

The entry 420d features a 2.0-litre turbo-diesel engine producing 135kW of power at 4000rpm and 380Nm of torque from 1750-2750rpm. Via the range-standard eight-speed automatic transmission (a six-speed manual gearbox is a no-cost option), the oil-burner is the fuel efficiency leader of the range, using a combined 4.8 litres per 100 kilometres and emitting 127 grams of carbon dioxide per kilometre. It also features idle-stop technology to save fuel while stopped in traffic.

Standard equipment, even at base level, runs to 18-inch alloys shod in run-flat rubber, front and rear parking sensors linked to a reversing camera that shows up in the 8.8-inch LCD screen mounted high on the dash, dusk-sensing bi-Xenon headlights, and a self-dimming rearvision mirror.

There is also dual-zone climate-control air-conditioning, tinted windows, well-bolstered electric-adjust heated seats trimmed in leather with a memory function for the driver, six-speaker audio with a USB slot, Bluetooth phone connection and a 20 gigabyte hard disk for storing music, and a high-end version of BMW’s satellite-navigation system.

Stepping up to the mid-range 428i brings a turbocharged 2.0-litre petrol four-cylinder engine under the bonnet. It produces 135kW from 5000-6500rpm, and 350Nm from 1250-4800rpm, while fuel use and CO2 emissions are 4.8L/100km and 157g/km respectively.

The 428i features 19-inch alloys and includes an anti-dazzle function to interior and exterior mirrors, electric-adjust lumbar support for the front seats, a Wi-Fi sharing system that piggybacks off a smartphone connection, and a richer-sounding nine-speaker audio system.

It also gains the Adaptive M suspension system that lowers the ride height by 10mm and allows the driver to dial up softer or harder suspension settings, depending on need.

As with other BMW models, buyers choose either the Sport Line, Modern Line or Luxury Line fit-outs that vary the look of the car as a no-cost option.

Stepping up to the range-topping – for now – 435i places a turbocharged 3.0-litre in-line six-cylinder engine under the bonnet that produces 225kW from 580-6400rpm, and 400Nm from a wide 1200-5000rpm. Despite its performance, the 435i uses only 7.7L/100km and produces 180g/km of CO2.

It wears high-performance four-pot callipers on its front brake discs, and includes variable steering that weighs up to add feel under heavier applications of throttle, as well as M features such as twin-spoke 19-inch alloys, a thicker steering wheel and other premium touches such as a blacked-out kidney grille and anthracite roof lining.

The range-topper also steps up with keyless entry, remote boot opening using a sweep of a foot under the rear bumper and opening or closing the roof via the key fob. The audio system jumps to a 12-speaker Harman Kardon unit, and the front seats feature an “Air Collar” that wafts warm air on the front seat occupant’s necks.

In terms of straight-line performance, the 420d will accelerate from 0-100km/h in 8.2 seconds, the 428i in 6.4 and the 435i in just 5.5 seconds.

Prices for the 4 Series convertible have risen in comparison with the 3 Series range it replaces, but BMW claims it has added about $3300 to the value of the car, including all the efficiency and performance gains the revised drivetrains add.

BMW 4 Series Convertible pricing*

420d (a)	$88,800
428i (a)	$97,500
435i (a)	$126,600

*Excludes on-road costs.