BMW Z4 2009 Review

Built to take on the latest Porsche Boxster and a host of other quality topless Europeans, the Z4 - launched today in Spain - finally gets the muscle that its body deserves.

Bigger, beefier and subjectively beautiful, it also gets 225kW of bi-turbo 3-litre performance and a dual-clutch gearbox borrowed from the 335i models. And that's just for starters.

Arriving in Australia in May, the Z4 comes only - at least officially - as a retractable alloy-panelled convertible. To prevent confusion with its other rag-top models, BMW now calls this latest Z4 a Roadster.

The three model Z4 range - sDrive23i, sDrive30i and sDrive35i - has a choice of three engines - 2.5 and 3.0 from the previous Z4 and the bi-turbo 3.0 - and three transmissions that comprise six-speed manual and automatics and the seven-speed dual-clutch box that is optional only on the sDrive35i.

Pricing jumps $8000 for the entry-level sDrive23i - despite its numbers, it's actually a 150kW/250Nm 2.5-litre six - which will enter Australia at $86,200 as a six-speed manual and $89,500 as the auto. This replaces the Z4 2.5si that was $78,200 manual and $80,800 as an auto.

Step up to the 190kW/310Nm sDrive30i at $98,100 - $101,400 - compared with the outgoing 3.0si at $91,400/$94,000 - and the 225kW.400Nm sDrive35i at $116,900 as a manual and $120,400 with the dual-clutch box.

Though some buyers see the new Z4 as lining up against the Boxster, BMW sees it differently. It compares the 23i roadster with the Mercedes SLK200K, Audi TT 2.0 Roadster and the Alfa Romeo Spider 2.2.

The 30i challenges the Alfa Spider 3.2 V6, Audi TT 3.2 V6 and the Boxster. Here, up against the Porsche, BMW figures show its Z4 is quicker - 0-100km/h in 5.8 seconds compared with Porsche at 6.1 - and on par for fuel economy despited weighing 115kg more and having a 300cc bigger engine.

Up against the Porsche Boxster S, the Z4 35i is quicker to 100km/h by 0.2sec at 5.2, and more frugal at 9.8 litres/100km compared with the 10.6 l/100km.

However, data provided by BMW Australia for the comparisons appear to be based on the previous Porsche model. Porsche updated its Boxster range in January with its dual-clutch PDK transmission, direct petrol injection and weight reductions.

BMW says the Z4's two-piece aluminium folding roof erects or collapses in 20 seconds and stores within the boot.

The bigger body of the Z4 compared with its predecessor allows more cabin and boot space, though the intervention of the roof panels into the snub tail of the Z4 more than halves luggage capacity from 310 litres to 180 litres. However, there is an optional kit that creates a luggage hatch from boot to cabin to take a golf bag.

Driving

Two turbochargers acting on six cylinders in a two-seater body. You could virtually relay the driving feel of BMW's new Z4 on the data alone.

Or perhaps not. For though BMW unashamedly takes on Mercedes-Benz and Porsche two-seat roadsters, it is clearly doing it on its own terms.

Hunting the thousands of hills outside of Alicante in Spain in a bi-turbo Z4 - the top of the three model range that comes to Australian showrooms in May - shows that the company has strived to get its 225kW engine to be all things to all drivers in a chassis that, also, has to be sporty yet comfortable. Then it must be safe, fuel efficient and roomy - all nearly impossible targets yet BMW comes very close to pulling it off.

In Spain yesterday, BMW handed out the keys only to its sDrive35i - the convoluted name for the 3-litre bi-turbo version - with its seven-speed dual-clutch transmission. None of the other two, more lowly-specced Z4s were offered for a test drive.

It is clearly a good thing. Quite beautiful in the metal and bigger than pictures relay, it sits low and wide and not to distant in appearance to the company's more lavish - perhaps more excessive - 6-Series.

The 35i has been tuned for the owner who likes the gutteral sound of six cylinders being urged along by two turbochargers. Even with the metal roof engaged, the sound is musical and under the command of the accelerator pedal, runs through the scales from gentle thrum to a spine-chilling scream that is interrupted by an aggressive bark on the downshifts.

Take the roof down and its all the same, just louder.

The beauty of the bi-turbo engine is its breadth of power and torque delivery. It can rumble along in low revs and yet recover quickly to make gear upchanges and downchanges seemingly unnecessary. That makes it easy to drive but difficult to pick a sweet spot. That's not a complaint, just a fact.

The appearance of the Z4 is low and wide and certainly that's confirmed once inthe driver's seat. The cabin is surprisingly spacious, has a goodly range of storage spaces and the light-coloured plastics and fabrics - together with expansive glass - make it bright and airy. And that's with the roof up, so it's a welcome cabin for a convertible.

The dual-clutch box drives through BMW's now ubiqitous PlayStation gear toggle in concert with double-action steering wheel paddles for the manual mode. Like the Porsche PDK paddles, it's not the best system and certainly doesn't enhance manual gearshifting. The gearlever action, however, is spot on.

BMW offer three gearshift modes - standard, sport and sport plus - with the last two also sharpening up the response of the steering, accelerator and suspension systems. Sport gives a little bit of leeway before calling in the electronic stability and traction control nannies, while Sport Plus lets it all rip by disengaging everything. My preference was Sport. The standard mode has a bit of lag in its changes while flicking gthe console button to Sport and using the gearbox manually just makes it a bit more fun and slightly more engaging.

The standard mode will excite most owners. Sport will make the passenger pay attention while Sport Plus is simply too wild for the street unless in trained hands.

And here's the thing - this car has an engine that will put most of its rivals to shame and the Z4 35i clearly has the performance to awake any jaded soul. But the whole package is wrapped in cotton wool. You can push this car hard - very, very hard - and it will scare you so much your teeth will sweat. But it's held together by sophisticated electronics that are working overtime to keep the car on the road and its increasingly over-confident driver as safe as possible.

These electronics create something akin to an artificial driving experience. The rawness of the car is polished out and in its place is a package that while a tad surreal, perfectly suits a broader range of drivers. People who love driving will love this car. People who don't get a thrill from sitting behind the wheel will love it because it's so easy to drive. Is this the perfect sports car.

BMW has rid itself of the overly assisted Active steering system and in its place is a better feel that delivers the best of parking and high-speed manouevres. The wheel sits high on the dash predominantly because the driver sits so low. That ordinarily ruins visibility and BMW doesn't disappoint with a bonnet that stretches somewhere up front and an invisible tail behind.

Parking aside, the driver may find the car a bit wide in some circumstances - I swallowed my heart about a hundred times through the tight twists of the Spanish mountain passes - but once familiar, will be in awe of its directional stability and comfort.

Comfort in a sports car from BMW. Thanks to electronic dampers, the Z4 rarely puts its occupants in pain. The suspension monitors road surface changes and instantly adjusts. If the front wheel encounters a pothole, the damper valves open to reduce the thump and while doing that, tell the rear wheels that a bump in on its way.

The seats are short on the cushion and that is normally a problem. However, it doesn't impair comfort and actually gives the driver a bit more space to move around in the seat.

On sale - May

Price: sDrive23i $86,200 manual, $89,500 auto; sDrive 30i $98,100 manual, $101,400 auto; sDrive 35i $116,900 manual, $120,400 dual-clutch

Engines: Six-cylinder inline with variable-valve timing and lift, 2.5-litre, 3-litre and 3-litre bi-turbo

Outputs: 150kW @ 6400rpm - 23i, 190kW @ 6600RPM - 30i, 225kW @ 5800rpm, 35i

Economy: 9.2 l/100km, 23i and 30i, 9.8 l/100km, 35i manual

Performance: 0-100km/h - 6.6sec, 23i, 5.8sec, 30i, 5.2sec, 35i

Transmissions: 6-speed manual or auto, seven-speed dual clutch, rear drive