2009 BMW Z4: More than just a quick peek in the trunk

Over the decades, BMW has produced some exceptional sports cars, from the 328 that emerged victorious in the Mille Miglia open-road race to the 400-hp Z8. However, the Z3 and the first Z4, launched in 2003, have won over a much broader fan base.

This spring, the Bavarian manufacturer is replacing the Z4 roadster with a car that bears the same name but is far more ambitious. The new Z4 is bigger and more spacious than its predecessor, but what really sets it apart is a retractable hardtop which replaces the softtop.

With its more powerful engine and longer chassis, this new Z4 will also be able to challenge the Porsche Boxster, its other rival, in terms of performance and handling.

Two flavours

Two versions, differing from one another essentially by their engines, will be available starting on May 9. Both have a 3.0-litre six-cylinder engine, but the Z4 sDrive30i’s engine is naturally-aspirated, while the Z4 sDrive35i is powered by two turbochargers. These engine types are already in use on a few other Series at BMW.

The sDrive30i’s engine features 255 horses at 6,600 rpm and its maximum torque is 220 lbs-ft at only 2,600 rpm. According to the manufacturer, it goes from 0-100 km/h in 5.9 seconds with the factory standard 6-speed manual transmission, and in 6.3 seconds with the conventional automatic transmission, which also has six speeds.

The sDrive35i’s straight-six biturbo reaches 300 hp at 5,800 and its 300 lbs-ft torque is accessible from 1,400 to 5,000 rpm. BMW assures us that this new sports car needs only 5.3 seconds to go from 0-100 km/h with the factory standard 6-speed manual transmission and a tenth-of-a-second less (5.2 seconds) with the optional 7-speed automated dual-clutch sequential gearbox.

Form and function

Interestingly, the new Z4 is the first BMW designed entirely by female stylists. Juliane Blasi and Nadya Arkaout, both German, won an internal competition among the manufacturer’s stylists and thus, they were entrusted with the mission of designing the shape and the passenger compartment respectively.

The new Z4 looks a lot like the previous model with its sculpted and slightly concave sides. With the hardtop in place, it looks like a coupe or a classic Grand Touring car, with an elongated hood and a tail end that seems to end abruptly. Visibility is improved substantially by the roof’s straighter uprights, the four side windows and the glass rear window.

The new model’s nose is pointier and those typical BMW kidneys are more pronounced, but it is the tail end that has undergone the most significant changes. The higher, rounder trunk lid is immediately reminiscent of the 6 Series convertible. The Z4 has also grown longer by almost 15 cm, which will, above all, help contain the retractable roof and still have a very reasonable cargo volume that increases from 180 to 310 litres.

And how’s this for an idea: An optional passage between the trunk and the passenger compartment that allows you to transport two pairs of 170 cm skis or a snowboard, in a waterproof bag, or even a standard golf bag for would-be Tigers. It’s a first in this category.

More inviting

Although the new Z4’s wheelbase is only one millimetre longer, the cabin is a little more spacious overall, especially for the shoulders, where there is 20 mm more room. The openings for the doors are also 26 mm larger. The engineers have nonetheless designed a body that is 25% more torsionally rigid, which is good news for safety, for vehicle handling and for the proper functioning of the retractable roof.

The roof’s two aluminum panels fold back into the trunk or come out of it in 20 seconds. It’s definitely the quietest one out there. You activate it using a button on the console or on the remote lock, if you go for the optional Comfort Access system. With this option you can also place baggage in the trunk or remove it when the top is folded down by lifting the trunk lid and the roof toward the rear.

The driving position is quite decent and the optional sport seats offer good lateral support for the back with the adjustable seatback, but a more sculpted cushion would have been better in order to get the same result for agressive driving.

The more fluid design of the new dashboard is much appreciated. There are two large classic dials that are visible just in front of the driver's eyes, between the spokes of the impeccable steering wheel with its rim covered in smooth, fine leather. The four climate control dials seem a little cheap and minimalist at first, but you get used to it.

The Z4 is also equipped with the latest version of the infamous iDrive interface control, which has been widely and justly criticized since its creation. It is part of an options package that includes a navigation system that is connected to an 80 GB – of which 15 GB are for music files – hard drive.

If the iDrive works very well, it’s thanks to the seven buttons that surround it, like shortcuts to the main menus and functions, but also thanks to the superb, almost 9-inch (22 cm) Control Display screen positioned on top of the dash above the central console. This very clear and sharp screen remains visible and readable even with the top down and the sun shining, with sunglasses.

The manufacturing and trim quality of the cars driven during the launch in Spain was beyond reproach. All of the sDrive35i models equipped with almost all of the available options were there. The leathers used are treated to reflect the sun and reduce the accumulation of heat by up to 20 degrees.

Options packages

All versions of the Z4 come factory standard with DDC (Dynamic Driving Control) that helps you choose between three driving programmes at the touch of a button. DSC (Dynamic Stability Control) also comes factory standard and is an anti-skid control that offers various response thresholds defined by the DDC and also adjusts the rear brakes to create the effect of a virtual limited slip differential.

An optional Sport package includes performance tires on 19-inch alloy rims and the adaptive M suspension with ZF shock absorbers whose compression and expansion rates can change instantly. The Z4 also becomes the first in its category to be equipped with an electromechanical parking brake.

Furthermore, with the increased power and better performance that the sDrive35i’s biturbo engine brings, Friedbert Holz, spokesperson for the Z4 and the 3 Series at BMW AG affirms that there will not be an “M” version for the new model to replace the Z4 M models of the first generation.

The only model available at the time of the world press launch was the sDrive35i equipped with virtually all of the existing options. Its 7-speed sequential gearbox and automated dual-clutch is very efficient but is sometimes going to pass the next gear or downshift by one or two gears when you’re driving energetically, in turns. I briefly drove an sDrive35i with a manual gearbox and I found it very convincing, with its rapid, solid and precise stick shift.

When the top is up, the Z4 is very quiet. As soon as it disappears into the trunk, the irresistible roar of the engine washes over you.  Its secret is the muffler, which is unlike that of the 335i, 135i and the like. Driving with the four side windows up and the optional windscreen installed between the two roll bars behind the seats, there is just enough wind to tussle your hair and make the ride fun.

Multiple personalities

Each programme of the factory standard DDC maximizes the settings of components such as the drivetrain, the anti-skid control, the electromechanical steering and the variable rate shock absorbers of the Sport package. In Normal mode, the Z4 feels like a classic roadster, with slightly lethargic steering and an awkward front end. Fortunately, things tighten up in Sport mode but the traction control warning light flashes at the slightest movement of the gas pedal.

However, it’s in the DDC’s Sport + mode that the sDrive35i shows its true colours. Shifting is crisper, the steering has less assist and the DSC will allow the vehicle to skid 10 degrees. Moreover, the Z4 remains impeccably stable even with traction control and anti-skid control completely deactivated. Coming out of a hairpin turn with the accelerator all the way down, there’s only a slight and easily manageable oversteer.

On the other hand, I just about had a heart attack the first time the Z4 went over a simple manhole. Even in Normal mode, the suspension and the Bridestone 19-inch run-flat tires reacted roughly. It would be a good idea to terst drive the models with factory standard 17-inch wheels.

With its increased power and better handling the Z4 can now take on its rival, the Porsche Boxster, on a winding road. And with its high quality assembly and a superb retractable roof, the Bavarian is now ready and waiting for the Mercedes-Benz SLK in terms of comfort and refinement.

The new Z4 brings together the best of roadsters and coupes and jumps up a notch in this ultra-competitive fight. 
 

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