First drive: 911 PDK redefines Porsche perfection
BY MARTON PETTENDY | 17th Jun 2008
On sale in Germany from July 5 and in Australia from September 20, the upgraded 911 Carrera and Carrera S models might not look much different but offer more power, performance and real-world driveability – as well as lower fuel consumption and exhaust emissions.
The impressive double-act comes largely as a result of a direct fuel-injection (DFI) system similar to the one that debuted on the Cayenne’s larger 4.8-litre V8, which was released in the facelifted Porsche SUV in Australia in March 2007.
In its first application on Porsche’s famed horizontally-opposed six-cylinder boxer engines, DFI is fitted to all-new versions of both the rear-drive 911 Carrera’s 3.6-litre flat six and the 3.8-litre boxer engine that powers the Carrera S.
The same new engines will soon also appear in the all-wheel drive Carrera 4 and Carrera 4 S coupe, cabriolet and Targa models, and direct-injection is expected to provide an even bigger relative boost in performance and economy for next year’s updated 911 Turbo flagship.
DFI will also appear on the facelifted Boxster and Cayman’s new 2.7 and 3.2-litre flat sixes, due to debut at this October’s Paris motor show.
Both 911 engines now produce the naturally-aspirated specific engine output benchmark of 100hp and 110Nm per litre for the first time.
Maximum power output for the base 911 engine is up by 15kW, from 239kW to 254kW, while the Carrera S flat-six now produces 283kW – up a substantial 22kW from 261kW.
Peak torque, meanwhile, rises by 20Nm for both engines - from 370 to 390Nm in the 3.6 and from 400 to 420Nm in the 3.8.
Also making a contribution to both performance and fuel economy is the 911’s optional new PDK automated manual gearbox, which finally replaces Porsche’s aged five-speed Tiptronic S automatic.
The move will see the 911 join direct rivals like Nissan’s new GT-R (here in early 2009) and BMW’s M3 M-DCT (due on sale this month) in offering a self-shifting sequential manual.
But while the BorgWarner-developed rear transaxle unit in the GT-R has six speeds, the 911 joins the M3’s Getrag-sourced unit with seven – and also matches its launch control function, albeit as part of the optional Sport Chrono Plus package.
Porsche’s first production twin-clutch transmission will be supplied by German transmission specialist ZF, which also supplies automatic transmissions for the Boxster and Cayman.
Like VW’s DSG, Porsche’s PDK transmission differs from conventional automatic, manual and continuously variable transmissions by being a fully manual gearbox that comprises two clutches that activate two separate sets of pre-selected gear ratios.
It can be used in fully manual or automatic modes, and is both quicker and smoother than a single-clutch sequential manual gearbox (SMG) as found in the M5 and previous M3.
Porsche makes no bones about the fact that PDK versions are now the heroes of the 911 range, banishing the five-speed auto forever and leapfrogging the conventional six-speed manual models too.
The manual 911s still offer the highest top speeds, albeit by only 2km/h over their PDK equivalents, but PDK versions offer quicker acceleration – even when they’re not fitted with the optional Sports Chrono Plus pack’s launch control system.
The (3.8) Carrera S Coupe manual’s extra top-end engine performance now gives it a top speed of 302km/h (up 9km/h), almost matching the previous-generation GT3 and Turbo flagship 911s. The 3.8 PDK coupe is capable of a neat 300km/h – 15km/h faster than the 3.8 auto it replaces.
In entry-level 3.6-litre guise, the 911 coupe manual is good for 289km/h (up 4km/h), while the PDK version can hit 287km/h – 7km/h faster than the MY08 911 3.6 auto.
In terms of 0-100km/h acceleration, the 911 Carrera coupe manual is one-tenth quicker at 4.9 seconds, while the Carrera S coupe manual also drops a tenth to 4.7 seconds. But the PDK versions better both manuals by two-tenths, affording the 3.6 coupe a sprint time of 4.7 seconds and making the 3.8 even quicker at 4.5 seconds.
While that’s a whole 0.8 seconds quicker than their automatic predecessors, the sprint time reduces further with the optional Sport Chrono Plus pack’s launch control system, which knocks a further two-tenths off the 0-100km/h sprint time (4.5 for the Carrera and 4.3 for the S).
That's within about half a second of the top-shelf 911 Turbo, which does the 0-100 sprint in 3.9 seconds as a manual and 3.7 seconds as an auto - but will undoubtedly be quicker again as a PDK.
Despite the extra power and pace, Porsche says that combined average fuel consumption for the manual Carrera coupe drops by six per cent, from 11.0 to 10.3L/100km, while the Carrera S manual coupe is eight per cent more economical, 11.5 versus 10.6L/100km.
In the PDK guise the gains are even greater, with both the Carrera coupes 13 per cent more frugal - 11.2 down to 9.8L/100km for the 3.6 and 11.7 down to 10.2L/100km for the 3.8.
As a result, CO2 emissions fall by a similar margin, with the Carrera coupe manual nine per cent cleaner (266 versus 242g/km) and the Carrera S coupe manual 10 per cent better (277 versus 250g/km).
PDK versions of both 911 coupes emit 15 per cent less CO2 emissions – from 270 down to 230g/km for the 3.6 and 283 down to 240g/km for the 3.8 Globally, Porsche expects PDK versions of the new 911 to be more popular than the Tiptronic S versions they replace, with the split increasing from one-third to about half, which is the current 911 manual/auto split in Australia.
Apart from their cleaner, more frugal, more compact and more powerful engines, mated to a more effective and efficient alternative to the standard six-speed manual, the facelifted 911 coupe and cabrio also score subtle cosmetic updates, including new front and rear bumpers.
There is also upgraded equipment including a third-generation “PCM3” version of the Porsche Communications Management (PCM) system, comprising a bigger new 6.5-inch touch-screen. It can be optioned with satellite-navigation including a 40GB hard drive, plus voice control and a TV tuner.
Also new are headlights incorporating bi-Xenon headlights with washers and daytime LED running lights, while Dynamic Bending Lights also join the 911 options list.
The additional standard specifications cancel out the slight reduction in engine weight, with kerb weights increasing between 5 and 20kg.
The Carrera coupe manual rises 20kg, from 1395 to 1415kg, while the PDK version is 10kg heavier than the Tiptronic S version it replaces, 1445 versus 1435kg. The Carrera S coupe manual is 5kg heavier (1420 to 1425kg), while the PDK version is up the same amount, from 1455 to 1460kg.
Australian standard specifications will also include rear parking sensors and Bluetooth connectivity, but Australian pricing will not be finalised until the fate of the proposed increase in the luxury car tax has been decided.
“The price will go up – how much depends on the luxury car tax,” said Porsche Cars Australia managing director Michael Winkler, who added that the MY09 911 coupe and cabrio will rise in price by $10,000 without factoring in any LCT increase – which is said to represent the value of the increased standard equipment.
Expect PDK versions to attract a $6500 premium over their manual equivalents.
Drive impressions:
DON’T be fooled by its virtually identical exterior, because beneath the facelifted 911’s same-same skin lie almost as many changes as the current Porsche sports car flagship offered when it arrived in Australia in October 2004.The four-year-old 997-series coupe was the first 911 to be available with two different engines, housed is an all-new bodyshell that was both bigger and more rigid than the 996-series it replaced. Other new items included bigger brakes and wheels, a variable-ratio steering rack, standard stability control and extra airbags.
Now Porsche improves the breed again with two all-new engines that share only their 3.6 and 3.8-litre displacements with the model they replace, both mated to Porsche’s ground-breaking new PDK automated manual transmission, which replaces the aged five-speed Tiptronic S auto option.
The new flat six engines feature more oversquare cylinder dimensions and reduced friction, allowing them to rev higher while delivering more performance at lower revs. But even more effective is the fitment, for the first time in a Porsche boxer engine, of direct fuel-injection.
Those familiar with the 911’s famed flat sixes will instantly notice the crisper, lumpier and more metallic engine note, which gives the unique engine layout even more character – especially as the revs rise.
Crack open the throttle and the improved response of both the 3.6 and 3.8-litre sixes is obvious, with both engines barking into action more quickly than before, then offering a wall of midrange torque and an more eager top-end power surge, which now extends a further 300rpm to 7500rpm - despite the fact both engines produce their peak power outputs 100rpm earlier at 6500rpm.
Driven in isolation, the standard 911 Carrera coupe and cabriolet’s 3.6-litre boxer offers enough standing-start acceleration violence, V8-like in-gear flexibility and top-end briskness to intoxicate even the most hardened supercar junkie.
But mash the accelerator pedal in the S-badged Carrera and the 3.8-litre’s new-found response to throttle inputs and meatier power delivery right across its extended rev-range introduces a whole new world of naturally-aspirated boxer performance.
One can only wonder what incremental performance gains the combination of direct-injection and Porsche’s mind-blowing 911 Turbo engine will produce, but the atmo 911 has clearly taken a giant step closer to what is the world’s finest six-cylinder engine.
Incredibly, all this extra outright performance and real-world driveability comes at no expense to fuel consumption. In fact, improvements of up to eight per cent have been made on manual models and the cars we drove averaged around 15L/100km – even after 300km of super-high autobahn speeds and country-road scrapping around rural Germany.
Matched to Porsche’s brilliant new PDK transmission, the facelifted 911 drops its claimed average fuel economy figure by no less than 13 per cent – to below 10L/100km in the base Carrera coupe’s case.
And after sampling the all-new dual-clutch seven-speed automated manual, we can see why.
Forget the 911’s tired but still reasonably effective old five-speed Tiptronic S auto, because PDK delivers everything it did – and a whole bunch more. More too, in fact, than the conventional six-speed manual gearbox, which carries over.
Automatic 911 drivers will love the way the Carrera PDK changes gears, both up and down, more quickly and more seamlessly. And they’ll revel in the familiarity of being able to shift gears via either the gearshifter itself or via the two identical shift paddles mounted on either side of the steering wheel.
They may choose to simply leave it in Drive and let PDK do its thing, or to override it on the odd occasion by flipping a paddle to hold a gear into corners or to change up to idle past the shops.
Instead of the former Tiptronic auto’s rocker switches on the spokes, however, PDK comprises push-pull paddles that are part of the spokes – pull either one of them towards you with your fingers to change down, or push either one away to change up.
As it happens, this – along with the fact the gearshifter changes up by pushing forward, as before – is our only gripe with PDK.
Though it’s a matter of personal taste and owners will become accustomed with either method, we think it’s more natural to push the lever or paddles forward to change down and pull back to change up – just as the semi-auto transmissions do in Fords and BMWs.
Either way, the result is silky-smooth gearchanges that are a match for any true auto and, in Sport mode, rapid-fire shifts that are significantly more violent but much quicker than Volkswagen’s similar DSG system.
At no time, however, did PDK sound as clunky as the Nissan GTR’s six-speed transaxle dual-clutch system made by BorgWarner, or as jerky and indecisive in slow-speed parking situations as the sequential manual transmission found in BMW M5 and previous M3.
Fitted with the optional Sports Chrono Plus pack, the 911 PDK’s new launch control system works with clinical effectiveness, revealing just how much the car’s rear-engined layout optimises standing-start traction. Brutally quick getaways are on demand, simply by tramping on both the throttle and brake pedals, then releasing the latter.
We’re yet to sample the forthcoming M3 M-DCT’s similar seven-speed Getrag-supplied dual-clutch transmission, but will be surprised if it can match the effectiveness of the Porsche’s launch control system, let alone the obvious refinement and lack of driveline snatch it comes with.
Don’t misunderstand: To GoAuto, a 911 without a clutch pedal is like breakfast without coffee, an SUV that never goes off-road or a motorshow with no luxury brands. To the Porsche purist, it’s just plain sacrilege, because shifting your own gears in a 911 - or a Boxster or Cayman, for that matter – remains one of motoring’s richest rewards.
Done properly, there is nothing more satisfying than the sublime shift feel and function of a manual 911 while dancing on three pedals with heels and toes on a twisting mountain pass.
Throw in the facts that a manual 911 will: save you more than $6000, eliminate PDK paddle confusion, offer unequivocally full manual control, deliver a 2km/h higher top speed, rev all the way to the 7500rpm cut-out (rather than shifting up at 7200rpm in auto mode) and smoke its rear tyres at will, and the argument for a manual transmission appears done and dusted.
But if the 911 in question is your daily driver, then consider that the PDK version: is easier to drive both around town and in anger, will never make you tired of changing gears, won’t allow the embarrassment of stalling it, is more economical, is even more user-friendly and functional than the auto it replaces, offers quicker acceleration and the bench racing bonus of a ballistic launch control function.
Forget the other changes to the facelifted 911, even if the bigger new touch-screen is more ergonomic, the slightly wider rear wheels look more fearsome and deliver more grip, and the bi-Xenon headlights with washers and LED running lights look more high-tech.
The upgraded 911 will be at least $10,000 more expensive than before and, after 25 years in the making, the PDK version will attract a further premium. But it was worth the wait.
The PDK-equipped MY09 version represents the 911’s greatest transmission advance since the four-speed Sportomatic emerged in 1968. The only pity is it will take trainspotters to notice it.