BMW Z4 sDrive35is 2010 Review

BMW Z4 sDrive35is

What we liked
>> Powerful engine
>> Exterior design
>> Classy interior

Not so much
>> Front end feel
>> No 'M' badge
>> Luggage space

OVERVIEW
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In fact, lined up next to the manual version of the V8-powered M3 Coupe in a drag race, the two-seater Z4 drop top keeps pace, accelerating from zero to 100km/h in 4.8 seconds. More than just a boulevard poser, this particular Z4 has real muscle.

Though the car's full name doesn't exactly roll off the tongue, the BMW Z4 sDrive35is has been designed to get pulses racing, a combination of more power and torque, matched to a sports-tuned adaptive chassis and topped off with an aggressive new stance elevating it above the current Z4 crop.

Designed to give the Porsche Boxster S and Audi TT RS a run for their money, BMW Australia will bring only 25 units of the high performance car into Australia in 2010, with another 25 earmarked for 2011, ensuring exclusivity.

Voice control, sports seats with electronic adjustment, anti-dazzle mirrors, adaptive headlights with high beam assistant, auto windscreen wipers and an M sports package (which adds the aggressive ground effects and a plump steering wheel) round out the standard features list.

Priced in the same ballpark as the $136K Audi TT RS and the $131k Porsche Boxster S, BMW's new Z4 halo model has been priced and specified to attract buyers who would have traditionally approached its German competitors.

BMW Australia revealed that of the 25 cars coming here in 2010 several are already spoken for, which augurs well for the go-fast show pony.

MECHANICAL
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The German carmaker has made tweaks to the engine control unit (ECU) and exhaust system and upped the turbochargers' boost levels, giving the engine more herbs and spices. How much exactly? Well, with an extra 25 kilowatts of power and 100Nm of torque – for a grand total of 250kW/500Nm – the engine now pushes the car's 1525kg bulk around with more gusto than the standard six-cylinder turbo's 225kW/400Nm.

The zero to 100km/h sprint takes just 4.8 seconds, in part thanks to the engine's 500Nm of torque in overboost mode, and also due to the new seven-speed dual-clutch automatic transmission. The overboost function is claimed to last for up to 10 seconds.

Simply wait for the traffic lights to go green, then mash the accelerator pedal and the car launches forward with the gait of a thoroughbred. It's true that this engine is powerful -- and with peak torque arriving at low engine speeds (1500rpm!) it hits its stride incredibly rapidly -- but is also relatively refined, even when it's huffing and puffing under extreme duress.

Interestingly, BMW has managed to keep fuel consumption the same as its less powerful sibling, the Z4 35i, at 9.0L/100km. And thanks to a few muffler tweaks the engine is more outgoing (read: louder) than other Z4 models, providing the car with far more presence as a result.

The chassis setup is similar to other Z4 models in that it maintains independent suspension all round -- double-joint spring strut front axles up front and central link rear axle). The new car rides 10mm lower and features adaptive damping technology. The latter feature automatically adjusts individual shock absorbers' damping levels based on sensory feedback, such as lateral acceleration and so forth. The end result is supposed to be less body roll and more traction heading into and out of corners.

Larger and wider 18-inch alloy rims allow for bigger tyres to deliver improved grip, and there are also subtle changes to the car's front and rear fascia design, creating for the two-seater a more aggressive persona.

Lastly, the steering comprises an electrically assisted system, with refinements made for this hi-po model. However it's interesting to note that BMW's M division prefers hydraulic steering setups...

The glovebox is tiny, and virtually useless for anything larger than a box of ciggies, and the boot isn't much bigger, especially when the top is dropped. With 310 litres of boot space with the roof over your head, and 180 litres when it's closed, I can happily report the roof didn't crush my satchel when transitioning. Furthermore, it takes 20 seconds for the roof to fully open or close.

While you won't be able to cram your Cannondale in the boot of this stove hot performance roadster, you will be able to hear birdsong as you cruise down the coast, smell native flora as you amble through the forest and taste acrid diesel as you wait in traffic on a balmy Wednesday evening.

SAFETY
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Designed not only stop you acquiring a face full of asphalt (or worse) should flip the vehicle, the roll bars also look pretty trick.

Cruise control is also part of the package while front and rear parking sensors will help keep the car's paint job safe – it becomes very useful when you realise how long the bonnet is and how low you sit within the car.

COMPETITORS
-- The Teutonic trio
Porsche, Audi and Mercedes-Benz are the main rivals, the Boxster S, TT RS and SLK 55 AMG drop tops respectively. BMW has positioned the Z4 sDrive 35is so that it trumps the Porsche in terms of equipment, power, performance and efficiency, and undercuts the Benz in price.

The $129,900 BMW Z4 sDrive35is comes in as slightly more affordable than the $136,814 Audi TT RS, but the Audi is the fastest vehicle out of the abovementioned four, with the Z4 coming in second place ahead of the Benz then the Porsche.

The moment the high performance Z4 ignited, it was clear that this was not your everyday boulevard cruiser. With each compact turbo working on three of the car's six-cylinders, the motive force that finds it way to the rear wheels provides the vehicle with effortless but accessible power. It's also a vocal engine, with sporadic pops and subtle backfires on the overrun, and the odd engine 'burp' between automated gearshifts.

This Z4 is fast. Not brutally so, but rapid in a controlled, ordered manner. It delivers the sort of power that won't catch you by surprise or unduly concern your passenger – peaky it is not – but is has a seemingly endless supply of grunt, happy to propel the car with astonishing ease.

Tactile response within the car is suitably luxurious, the leather sports seats well bolstered but comfortable, the suitably chunky steering wheel finished with pleasantly soft leather.

With the roof closed, the cabin is a relatively calm and quiet place to be, the hard charging engine the only indication that something exciting is happening.

Find a stretch of winding road and the BMW Z4 can be very quick point to point, getting its huge power reserves to the road with impressive ease. Grip levels are notable, but the one area where the car felt a little loose was in the front end, particularly the steering feel.

For the most part the car tips into corners as you'd expect it to, with precision and eagerness, but communication through the tiller (and the seat of the pants) isn't particularly clear, and if the road surface isn't billiard table smooth the car’s nose can easily get flustered – especially with a wide open throttle.

As good as they look, we would recommend against optioning the 19-inch alloy wheels, which reduce ride quality significantly when compared to the factory standard 18-inch hoops, in turn making the car even more skittish over mid-corner ruts.

There are three modes to the adaptive M sport suspension (sport, sport+ and normal) which affect not just the suspension damping levels, but also the steering, throttle and gearchange characteristics. It's actually not a bad system, lending a car the kind of flexibility that makes it equally adept at cruising or bruising.

By and large the BMW Z4 sDrive35is can be a very rewarding vehicle to drive but if the road surface is average and the driver is impatient it can be a handful.

Rather than shoving the car aggressively into corners, the BMW felt quicker and more predictable when approaching corners with less intensity, and dialling in more throttle after the apex. Indeed, blasting out of corners in the Z4 is a delight.

Though it shouldn't be seen as a deal-breaker, the BMW doesn't quite have the dynamic finesse of the Porsche Boxster S or constant traction of the Audi TT. Perhaps not the ball-tearing roadster we were expecting, that's not to say the top-spec Z4 can't be enjoyable to drive flat-knacker.

What the Z4 does deliver is eyebrow-raising straight-line performance, a sumptuous interior and an aggressive exterior design. For many drivers, these factors will be more than enough incentive to take a closer look.

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