This summer, Porsche is introducing the next generation of the 911, the latest version of the unique rear-engined concept that's been continually developed over its 45-year evolution in order that it remains relevant in changing times.
By introducing a range of new technologies, Porsche has built on the outstanding reputation of the 911 to further optimize the car for today's driving environment. All-new 3.6 and 3.8 liter flat-six engines will feature Direct Fuel Injection (DFI), and the option of the Porsche Doppelkupplungsgetriebe (PDK) double-clutch transmission, are highlights marking a quantum leap in the car's development.
The four new 911 models - two Coups and two Cabriolets - offer increased performance and efficiency. With either a six-speed manual gearbox or the PDK transmission, the Carrera Coup offers outstanding fuel economy of 29.4mpg combined. Furthermore, CO2 emissions of the 3.6-litre engine are down by up to 15%. And these engines, 13 lb lighter than before, also outperform European emissions regulations.
Standard on the Cayenne V-engines since 2007, Porsche is now moving over to Direct Fuel Injection (DFI) for the flat-six engines in the 911 series. Forming exactly the right mixture of fuel and air directly in the combustion chamber, this sophisticated technology serves to develop more horsepower and torque from less fuel.
As well as offering lower running costs, the direct fuel injection engines fitted in the 911 are also more powerful than the previous generation units. Maximum output of the 911 Carrera 3.6 liter is up 20hp to 345hp. Output of the 911 Carrera S 3.8 liter is equally impressive, up 30hp to 385hp. With this extra power, the Carrera S Coup now offers a top speed of slightly over 188 mph.
Direct fuel injection also serves to ensure `homogeneous' operation of the power unit with a consistent balance of the fuel/air mixture in the combustion chamber at all times and under all running conditions. Such operation guarantees optimum combustion, maintaining low emissions, without making any particular requirements in terms of fuel quality. Depending on engine load and speed, fuel is injected into the combustion chamber at a pressure of 120-bar. The big advantage is that unlike conventional intake manifold injection, direct fuel injection serves to form the fuel/air mixture directly in the combustion chamber. This better mixes the air and fuel in the cylinder, establishing an important prerequisite for clean and complete combustion.
With the evaporation of fuel reducing the temperature in the combustion chamber, the amount of air ingested may be increased accordingly, helping to improve the cylinder charge and the level of engine power. At the same time, the cooler fuel/air mixture allows a higher compression ratio in the interests of greater efficiency and extra power from less fuel. Thus, the combustion chambers in both the 3.6 and 3.8liter engines now have a compression ratio of 12.5:1, as opposed to 11.3:1 and 11.8:1 respectively on the previous engines.
The new generation 911 is available for the first time with the new Porsche double-clutch transmission. Offering seven forward gears, the new gearbox combines the driving comfort of a torque converter-equipped automatic with the dynamic manual gearshift functionality of a sequential racing gearbox. PDK also boasts an entirely automatic gearshift function, and replaces the Tiptronic S automatic transmission previously offered on the Carrera and Carrera S.
Through its optimised and adaptive gearshift programmes, PDK improves the acceleration of the 911 and reduces fuel consumption to a level even lower than before.
In principle, the PDK consists of a conventional manual gearbox and a hydraulic control system divided into two separate transmission units. Two wet clutches in radial arrangement, controlled hydraulically, and using oil for both cooling and lubrication, form the heart of the transmission. One clutch is for the first transmission unit with the uneven gear ratios (1,3,5,7) and reverse, and the other clutch is for the second transmission unit with the even gears (2,4,6). Via a number of pressure valves, the hydraulic control unit masterminds both the wet clutches and the shift cylinders activating the transmission ratio required.
The gearshift perceived by the driver comes not from the gears actually changing, but from the change of positive clutch engagement. In this case, the clutch on one transmission opens or disengages while the clutch on the other transmission closes or engages in a simultaneous process.
The big advantage is even faster gearshift than with a conventional manual gearbox or torque converter automatic transmission. The gears are already `in mesh' when shifting and the power of the engine need not be interrupted in the process.
PDK also reduces transmission power losses courtesy of the high standard of mechanical efficiency in the double-clutch, and this manifests itself in fuel economy improvements of approximately 13% compared with a conventional Tiptronic S transmission. PDK also offers an advantage in terms of weight - despite two additional gears, it weighs 22 lb less than Tiptronic S.Porsche first developed the PDK gearshift principle for motorsport 25 years ago. Porsche works drivers were able to accelerate faster than their competitors and keep both hands on the steering wheel while changing gears.The seven-speed PDK shifts gears up to 60% faster than a conventional automatic transmission, and naturally, gives the new 911 Carrera models even better performance: when equipped with PDK, the Carrera S Coup accelerates in 4.5sec from 0-62mph (0-100 km/h), another 0.2sec faster than with a manual six-speed gearbox - and 0.8sec quicker than its predecessor with Tiptronic S.And those customers in search of optimum driving dynamics have the option to combine PDK with Sport Chrono Package Plus, now featuring Launch Control. The result is high-speed acceleration from rest without wheel slip, combined with race-style gear shifting, enabling the car to accelerate to 62mph in 4.3sec.To use the various functions of the double-clutch transmission, the driver can either shift gears by means of toggles on the spokes of the new steering wheel, or via the new gear selector lever. The driver can press forwards to shift the gears up, and press them from behind to shift downwards. Alternatively, pushing the gear selector lever forwards shifts up a gear, and pulling it back shifts down. The option of PDK costs 2338, and the Sport Chrono Package Plus upgrade costs 729.
The Porsche Stability Management (PSM) system, which continues to be standard on the new 911, now also comprises the Brake Pre-Filling and Brake Assistant functions which ensures faster and more powerful braking response when required. These aspects were previously available only on the Carrera 4 and Turbo models. The 911 Carrera now also features larger 330mm diameter brake discs front and rear.
At first sight, the new generation 911 can be identified through innovations in design both front and rear. These include larger rearview mirrors, new 18" and 19" wheels and new lights featuring LED technology. With LED day-time driving lights and bi-xenon headlights now standard on all new models in the Carrera range, the 911 silhouette has continued to evolve, and its classic look is further emphasized by new LED rear lights. As a further option, Porsche now also offers Dynamic Cornering Lights on all models.
The interior has similarly evolved. Most obviously, the Porsche Communication Management (PCM) control system features a simplified control panel, plus a larger 6.5" display with `touchscreen' technology. PCM can now be fully compatible with external audio sources, such as an iPod or a USB stick, and Bluetooth. A TV tuner is a further option.