Porsche 911 2008 review

And those changes have enabled some of the biggest leaps forward in the 40-plus year history of the world's most enviable sports car.

The gains in fuel economy, performance, reduced weight and emissions are palpable.

As far as exterior giveaways go, the updated 997 series coupes and cabriolets remain discreet unlike the story hidden beneath.

DRIVETRAINS

These machines gain direct injection flat six cylinder engines in 3.6-litre (Carrera 4) and 3.8-litre (4S) and an electronic four-wheel-drive system that replaces the viscous coupling arrangement that has been used on the 911 for almost 20 years.

And as with its two-wheel-drive brothers, the C4 versions benefit from the seven-speed double clutch transmission called Porsche Doppelkupplungsgetriebe or PDK.

While there are seven gears, the first six ratios are evenly spaced with the final cog essentially an overrun for better economy and emissions.

Bristling with engineering advancements, the C4 and C4S offer generational gains with 8.5 per cent more power and use up to 12.9 per cent less fuel while the carbon emissions are lowered by 15.4 per cent.

The C4 coupe lifts from 239kW to 254kW yet reduces economy from 11.6litres/100km to 10.1litres/100km with torque rising 20Nm to 390Nm

Gains for the 3.8litre C4S are 283kW (up from 261kW) and a reduction in fuel use from 11.9litres/100km to 10.5litres/100km with torque jumping 20Nm to 420Nm.

The PDK can either be accessed by the gearshifter or large buttons integrated on the steering wheel spokes which have come in for a deal of criticism for their awkward placement.

Already Porsche says it may review what it does for the all-new 998 (unofficial code) model which could be out by late 2010 and which could offer proper paddle shifters as well as the buttons.

EXTERIOR AND SPEC

On the outside afficianados will notice the definitive daytime running lights at the front, the neat LED rear taillight treatment and a reflector strip on the leading edge of the engine bay lid.

At 124kg the PDK unit, which is expected to command a $7000 option price, is just over 10kg lighter than the Tiptronic S unit it replaces but is 30kg heavier than the manual gearbox.

The PDK unit shares little with save for the in-principle idea of twin clutch technology, which Porsche used on its brilliant 956 Group C sports car racing programme of the early 1980's.

As a $2200 option, the Sports Chrono Package Plus system incorporates a launch control feature that is accessed by a SportPlus button that automatically dials up 6500 revs for the perfect getaway.

Another feature of the package is a meaner, angrier gearshift map accessed by the SportPlus button.

Sports Chrono also enables the driver to keep a log of their lap times and detect if you are slower or faster on any given lap.

SportPlus literally changes the personality of the PDK gearbox into an explosively response weapon where the shortest, sharpest gearshift points are accessed with shirt times claimed to be twice as fast as the outgoing Tiptronic S.

The argument against all-wheel-drive layouts continuing to have relevance because of their weight impost hurting fuel economy and performance doesn't ring true in the case of the Carrera 4.

Despite weighing 55kg more than a C2, a C4 has lapped Nurburging's Nordschleife circuit two seconds quicker than its two-wheel-drive equivalent by turning an impressive 7mins56sec.

The Carrera 4's new all-wheel-drive system is capable of shuffling torque by up to 100 per cent to either the front or the rear axles if needed where the previous system had limited maximum torque split of between 10 to 40 per cent.

DRIVING

Traditionally Porsche refrains from fiddling too much with the design clarity of the time-honoured 911.

There's good reason because the proportions, lines, swoops and curves are among the purest and prettiest in automotive car design.

No surprise then at a casual glance it's difficult for some to pick the updated Carrera 4 and 4S over the 997 series.

So 997.5, as we define it, offers mild styling changes with front and rear head and taillight LED and a red reflector at the back that returns over 10-odd years of non-service.

Behind the wheel the updated all-wheel-drive 911 coupe and cabriolets are a clear and decisive step forward.

On a 170km road drive in the Lowenberger region just outside Berlin, the C4 and C4S were put through a variety of smooth top roads, patchwork bitumen, lumpy and bumpy surfaces and narrow cobblestone lanes.

In retrospect it was a brave move putting the firm Carrera 4 coupe and cabriolet over those challenging conditions.

They were not roads that suited the Active Damping set up where ride height is lowered by 20mm in conjunction with the Porsche Active Suspension Management feature.

The ride on the super low profile 19-inch rubber that the launch car was shod with was not surprisingly jarring.

At times there was a tendency to pick up every little imperfection and corrugation on the road.

That said the real story is that the face-lifted car shows considerable steps ahead in driving dynamics and efficiency.

More weight to the steering and the dialling out of some push through corners together with a brilliant new electronic all-wheel-drive system give the new C4 and C4S a sharper edge.

There is a triple treat waiting for those interested in the upgraded cars with direct injection and the smart PDK transmission in partnership with the electronic AWD combining to give the C4 and C4S coupes and cabriolets even greater precision and surety.

At last a 911 driver can enjoy a truly masterful transmission that finally does one of the sweetest chassis's in the business justice.

Pleasing levels of refinement in low speed shuffling around car spaces and rolling away from standstill have been dialled into the new double clutch PDK 7-speed transmission.

It actually creeps forward from a stop without any throttle and while there is a bit of grumbling detected here and there when trawling the car park, the PDK is the best example yet of these wet/dry clutch systems.

In the Carrera 4 coupe sampled on this drive, the PDK unit had few faults although at times the palms of your hands accidentally pushed the button to upshift particularly if any reasonable amount of steering lock was wound on.

It's awkwardly placed and accidentally plucking an upshift is not desirable on a track day or tarmac rally when you're negotiating quick direction changes.

Together with the optional SportChrono system ($2200) when you apply the SportPlus button the gear shift points become more wildly aggressive.

The change down from third to second is particularly angry with a short, sharp blip that sends the 3.6-litre boxer engine's into a playful yelp.

Even in drive mode the gear selector readout on the Instrument Panel lets you know what gear you are in and the centrally located taco with digital speed readout strikes a happy combination.

It's not until you can legally open the taps that you comprehend what all the fuss is about when driving a 911.

A comprehensive drive at a former Russian airfield that saw serious service before the Berlin wall came down in 1989 was an environment made to order for one of the world's most definitive sports cars.

The Gross Drolln airfield is a huge base linked by a maze of concrete runways flanked by dozens of camouflaged steel and concrete bunkers once home to MiG fighter jets ready to wage a war that thankfully didn't happen.

Porsche used the airfield a few years ago to launch its Carrera GT supercar so it's no mickey-mouse deal for pretend sports cars.

Among the extensive network of runways and link roads there are two dedicated handling tracks, a skid pan and a 1.7km long runway for high speed testing.

The exercises which the C4 and C4S 911s were put through ranged from slalom skid pan runs, long and short handling tracks using ideal lines at maximum throttle and a top speed blast down the runway.

Apart from being more fun that being locked in a room full suffocating with laughing gas, the exercises proved several points.

On the slalom the C4 was driven both the stability systems functioning and turned off and the behaviour was, even for an all-wheel-drive layout, worlds apart.

It then begs the question why traction and stability aids like Porsche's PSM should be switchable in lesser marques than those from Zuffenhausen.

The new electronic all-wheel-drive set-up and the lockable limited slip rear differential (22 per cent lockable under power and 27 per cent in overrun) give the C4 tremendous confidence when pushed to the edge.

This 911 with its rear-end spread a further 44mm wider than the outgoing model, is so adaptable and balanced that the driver can entice it to behave any way they desire through a corner.

With small adjustments on the tiller and the throttle you can smooth out understeer mid-corner and gain maximum punch for the exit.

Acceleration times with the arrival of PDK have leaped ahead with 0-100km/h achieved in the C4 in 4.8sec, .8s quicker than the Tiptronic S transmission and 4.5s in the C4S, a similar gain over the previous model.

When the optional launch control is applied that cuts the time further with a 4.3sec acceleration time from a standstill to 100km/h.

The optional Ceramic Composite Brakes (approx $20,000), 350mm in diameter 20mm more than the standard package are monstrous in performance.

After flying down a V-max run and clocking close to a tick under 260km/h, you can trample the brake pedal as hard as you can muster and the car will pull up without any theatrics.

In that exercise there is a massive amount of force generated by the emergency stop that is said to be the equivalent of about 1800bhp.