Porsche Panamera Diesel, 2012

 

 

 

 

•  Porsche Panamera Diesel, 2012

From Berlin to Bologna on only one tank of fuel: With a range in excess of 1,200 kilometres (~746 miles) the new Porsche Panamera Diesel is a good bet as a distinctly economical GT saloon. The long-range cruiser with an impressive turn of speed combines the sporty attributes of Porsche's Gran Turismo family with typical diesel characteristics such as exemplary fuel economy and oodles of pulling power. In the process, the new four-door car provides yet another prime example of "Porsche Intelligent Performance", reflected in each and every development.

The engine characteristics of the new Panamera Diesel enable it to take sprints and climbs effortlessly in its stride. Typically for a diesel, 550 Newton metres of rated torque - 50 Nm more than for the Panamera S with V8 engine - are applied to the crankshaft between 1,750 rpm and 2,750 rpm. Twinned with the highly efficient eight-speed Tiptronic S, this power development enables the Gran Turismo to achieve in-gear acceleration from 80 km/h to 120 km/h (~50 mph to 75 mph) in 4.5 seconds, for example.

Visually the Porsche Panamera Diesel resembles the Panamera with the V6 petrol engine, the exterior difference being the "diesel" lettering on the front doors and the tailpipe covers specially developed for the diesel. In terms of its driving dynamics and comfort, the new fourdoor vehicle is a genuine Porsche Gran Turismo through and through. It features steel springs as standard. Porsche Active Suspension Management (PASM) adaptive damper control and adaptive air suspension with additional air volume are available as an option. This makes for a very wide spread of suspension characteristics with further enhance ments to ride comfort on the one hand and very sporty driving dynamics on the other.

The combination of such a high level of efficiency and performance cannot be achieved by high-quality drive concepts alone. The "Porsche Intelligent Performance" principle is also apparent in the rigorous lightweight design. For example, axles, doors, bonnet, wings and rear lid are made of aluminium to keep the vehicle weight low. Developed from the outset as a four-seater vehicle, in terms also of interior design and the individual comfort of each and every occupant the Gran Turismo ploughs its own furrow. Notwithstanding its distinctive flat and stretched silhouette, 4.97 metres in length and a mere 142 centimetres high, the Porsche Panamera Diesel sets the standard in its class for a sense of space on all four seats.

Highly efficient: V6 diesel with 2000 bar injection pressure
The three-litre, six-cylinder V engine under the Porsche Panamera Diesel's bonnet is the state of the art in diesel technology: Auto start/stop function, common rail direct injection through piezo valves at a pressure of 2000 bar, turbocharging employing an electrically controlled variable geometry turbocharger (VGT) and emission control achieved by controlled exhaust gas recirculation, oxidation catalyst and particle filter. This is how high performance, generous torque and low consumption find themselves accompanied by smooth running, reliability and low emissions. The Panamera Diesel satisfies the Euro 5 limit values and is approved accordingly. The V6 works so efficiently that only relatively little heat remains to be evacuated by the cooling water. To ensure comfortable passenger compartment temperatures despite cold weather the heating system is supplemented by an auxiliary heater.

Even more economical with auto start/stop function and electrical system recuperation
The Porsche Panamera Diesel features an auto start/stop function that automatically switches off the engine when the vehicle is stationary and the brake pedal is kept depressed - for example at traffic lights or in congestion. If the brake is released the system restarts the engine. The function's processes are optimised to such an extent that restarting is particularly spontaneous. The function economises on fuel and reduces CO2 emissions, without the driver having to modify his driving habits. Audio and communication systems continue to work despite the engine being switched off; the air conditioning system ensures that the selected temperature is maintained The engine restarts if more energy or cooling capacity is required. The auto start/stop function can be activated or deactivated by pressing a button. In certain situations the function is inactive, for example when the outside temperature is very high, on steep gradients or when the battery charge is low.

As in all Panamera models, electrical system recuperation also provides additional fuel economy with the battery being charged primarily during braking phases. When the car is accelerating, on the other hand, the alternator's charging current is reduced - the combustion engine doesn't need to supply as much power for charging the battery.

Basic engine with balance shaft, rocker arm and swirl flap
The basic engine in the new Porsche Panamera Diesel comprises a crankcase with two banks of cylinders disposed at an angle of 90 degrees to one another and made of vermicular graphite cast iron. A balance shaft is fitted to improve smooth running. The six cylinders have an 83 millimetre (~3.3 inches) bore, the piston stroke is 91.4 (3.6 inches) millimetres yielding a total displacement of 2,967 cc. The aluminium cylinder heads each accommodate two camshafts and four vertically mounted valves per cylinder. The valves are actuated by low friction rocker arms with hydraulic valve clearance compensation elements. The vertically mounted and centrally located injector is located directly above the central piston recess. This design ensures a good mixture formation, resulting in low fuel consumption and low exhaust emissions.

The manifold serving both banks of cylinders contains a continuously variable swirl flap. Depending on the engine speed and load, the swirl flap position controls the degree of swirl of the intake air. The flap is shut when the engine is idling and at low revs. This induces a pronounced swirl effect for improved mixture formation. From an engine speed of approximately 1,250 rpm, the flap is open continuously. The increased air throughput ensures that the combustion chamber is well charged. From an engine speed of approximately 2,750 rpm, the swirl flap is fully open.

Precision injection system with piezo-controlled injectors
The six-cylinder engine is supplied with fuel via a common rail system in which the diesel fuel is at a pressure of up to 2000 bar and is made available to the injectors by means of short injector rails. This presents three significant advantages: The injection pressure is virtually freely-selectable in the characteristic map, the high injection pressure permits an optimal mixture formation and the injection sequence with its pre-, main and post-injections can be designed to be very flexible.

The fuel is injected into the combustion chambers by piezo-controlled injectors that switch within less than one ten thousandth of a second. The opposite piezoelectric effect is used to control the piezo-actuator: At a voltage of 110 - 148 volts, the piezo actuator expands by up to 0.03 mm. This effect is applied to the nozzle needle, thereby opening the injection duct. Compared with magnetically controlled injection valves, in piezo technology the moving mass of the nozzle needle has been reduced by approximately 75 per cent.

This weight reduction makes for very short switching times, precisely controllable injection quantities and consequently several highly accurate injections per work cycle. In the Porsche Panamera Diesel engine as many as five partial injections per work cycle are envisaged depending on the operating point: At low engine revolutions the work cycle is initiated by two pre-injections, the injection of the main quantity is followed by two post-injections. This concept combines low emissions with a smooth combustion process.

VTG supercharger for optimal boost pressure adjustment
A variable geometry turbocharger and downstream charge air cooler supplies the combustion air. As in the 911 Turbo, the turbocharger features adjustable guide-blades which can be used to modify the turbine's pressure build-up characteristics. At low engine revolutions, the adjustable guide-blades make for high torque and good responsiveness by ensuring the turbine achieves a high pressure build-up and thus capacity for work with guide-blades "closed" and mass flow rates still low. When engine revolutions increase, the guide-blades are continuously opened, thereby ensuring the lowest possible fuel consumption by reducing the exhaust backpressure. The guide-blades are adjusted by an electric motor, ensuring very fast and precise guide-blade adjustment and thus spontaneous engine response.

At full load the maximum boost pressure is approximately 2.5 bar and is generated in excess of engine speeds of 1,750 rpm. To achieve a high cylinder charge and thus a spontaneous build-up of torque combined with low component temperatures, the air compressed, and thus heated, by the turbocharger has to be cooled back down again. This task is performed by two charge-air cooler on the side of the front-end.

Sophisticated exhaust system ensures exemplary low emissions performance
The sophisticated exhaust system ensures that the current Euro 5 standard limits are comfortably met. According to the engine's characteristic map, a proportion of the untreated gases is already fed back into the combustion process through the exhaust gas recircu lation circuit. The ensuing supply of inert gases causes the peak combustion temperature to be reduced, thereby cutting nitrogen oxide emissions. A cooler in the exhaust gas recirculation circuit ensures a further reduction in combustion temperature and also that a greater quan tity of exhaust gases can be recirculated.

Downstream of the turbocharger, the exhaust gases pass successively through the oxidation catalytic converter, diesel particulate filter (DPF) and silencer. The extent to which the particulate filter is clogged with soot is calculated by two pre-programmed clogging models in the engine control system. One of the models is calculated from the user's driving profile together with signals from exhaust gas temperatures and oxygen sensor. The other clogging model is provided by the flow resistance in the DPF, calculated using signals from the exhaust gas pressure sensor, the exhaust gas temperature sensor and air mass meter.

The particulate filter needs to be regenerated at regular intervals to prevent it from clogging with soot particles, thus impairing its operation. The soot particles that have accumulated in the particle filter are burned during the regeneration process. A distinction is drawn between passive regeneration of the catalytically-coated particulate filter (without involving the engine control system) and active regeneration (involving the engine control system). Both processes take place unnoticed by the driver. Thanks to DPF technology, particulate emission is as low as a mere 7.6 per cent of the permitted limit value.

Tiptronic S with special shift program
The Porsche Panamera Diesel is available exclusively with the eight-speed Porsche automatic transmission, the Tiptronic S. Its control program was specially tailored to the diesel engine: Because of the narrow speed range the shift point settings are totally different to those in the Panamera S Hybrid, which is the only other Gran Turismo to be equipped with the eightspeed transmission. In practice the Panamera Diesel's shift behaviour is largely similar to that of a Gran Turismo with PDK transmission. The shift points in the diesel Tiptronic S are customised to driving style and route profile. Alternatively, as is usual with Porsche, the gear can be changed manually by a rocker switch on the steering wheel or by lightly touching the selector lever. In order to transmit the V6's high torque with the minimum of loss, the converter features a lockup clutch. To save fuel, the Tiptronic S features stationary decoupling synchronised with the auto start/stop function, automatically selecting the neutral position if the foot brake is activated when the vehicle is stationary, the engine is running and the road surface is level.

Greater dynamics via the sport button
In common with all the other Panameras, the new diesel model enables the driver to press the sport button to choose between standard tuning and a sport mode. With sport mode activated, the engine responds more spontaneously and the accelerator pedal characteristic curve becomes steeper. The automatic transmission, along with air suspension and Porsche Active Suspension Management (PASM) if applicable, are also tuned to make them correspondingly sportier. The auto start/stop function is also deactivated.

Steel spring suspension as standard, PASM and air suspension if desired
The Porsche Panamera Diesel features steel spring suspension as standard. On the front axle it comprises fully load-bearing steel spring struts with integrated twin tube dampers and a spring damper unit on the rear axle. The new diesel model as well features aluminium double-wishbone suspension at the front and aluminium multi-link suspension at the rear for gui ding the axles. As a result, the steel spring suspension delivers sporty and comfortable handling, enabling the Panamera to respond instantly and with aplomb to different road surface conditions.

Active PASM is available as an option. This continuously adjusts the damper forces depending on road surface conditions and driving style. The damper settings can be adjusted by the driver in three stages - Comfort, Sport, Sport Plus. Porsche also offers adaptive air suspension including PASM as an option. This provides a load compensation levelling sy stem, three-stage height adjustment and controllable auxiliary volume for modifying the spring rate. This makes for a wide variation in handling between comfortable and very sporty.

Superior brake system, with ceramic system as an option
The Porsche Panamera Diesel's braking system is designed for performance with Porsche's trade mark stopping power. The braking power on the front axle is provided by six-piston aluminium monobloc fixed-calliper brakes and 360 millimetre diameter brake discs. Four-piston aluminium monobloc fixed-calliper brakes and 330 millimetre diameter brake discs are fitted on the rear axle. Porsche Stability Management (PSM), featured as standard, contains the brake assistant, vehicle-trailer stabilisation and the pre-filling of the brake system to reduce the stopping distance in emergencies. The electric parking brake automatically disengages when moving off. The particularly efficient and race-proven Porsche Ceramic Composite Brake (PCCB) system is available as an option for the Panamera Diesel as well.

Typical Panamera look with a unique personality
With its proportions redolent of classic Porsche design forms, the Porsche Panamera Diesel stands out in its vehicle class. The new model features halogen headlights as standard, the Bi-Xenon system is available as an option as are the cornering lights of the Porsche Dynamic Light System (PDLS). The side window surrounds are in matt black. The new diesel model features two oval single tailpipes in brushed aluminium that taper rearwards, thus emphasising the Panamera's dynamic rear profile. The Porsche Panamera Diesel runs on 18-inch alloy wheels with a five-spoke design fitted as standard, offering a glimpse of black brake callipers.

Interior equipment with all Panamera options
In terms of ambience and equipment, the Porsche Panamera Diesel's passenger compartment offers the typical elegant and sporty standard that is the hallmark of every Porsche Gran Turismo. The comfort seats with their electric eight-way adjustment of seat height, seat and backrest angle as well as fore/aft adjustment are included in the standard equipment. Taking this to the next level are the Comfort Memory Package with electric 14-way adjustment and the adaptive sports seats including Comfort Memory Package with raised seat side bolsters and electric 18-way adjustment available as an option. Heated driver and front passenger seats or heating for all four seats is available if desired. Similar to other models, the Porsche Panamera Diesel features two-zone automatic climate control as standard with separate temperature control and air distribution for driver and front passenger. Four-zone automatic climate control is available as an option.

The CDR-31 audio system is also included in the standard equipment with seven-inch colour screen, ten speakers and a total output of 100 watt. Taking this to the next level is the three stage offering comprising the Porsche Communication Management (PCM), BOSE® Surround Sound System or Burmester® High-End Surround Sound System. Also available as an option for the Panamera's V6 models as well are the familiar individual equipment options, such as for example ParkAssist front and rear, Porsche Entry & Drive or adaptive cruise control.

Specifications of the Porsche Panamera Diesel
    Displacement: 2,967 cc
    Bore: 83 mm (3.3")
    Stroke: 91.4 mm (3.6")
    Compression Ratio: 16.8:1
    Engine Power: 184 kW (~250 hp) at 3,800-4,400 rpm
    Max. Torque: 550 Nm at 1,750-2,750 rpm
    Power Output per Litre: 62.0 kW/litre (~84.3 hp/litre)
    Maximum Revs: 4,600 rpm
    Fuel Type: Diesel

    Performance
        Top speed: 242 km/h (~150 mph)
        0-100 km/h (62 mph): 6.8 s
        0-160 km/h (99 mph): 16.8 s
        0-200 km/h (124 mph): 30.4 s
        0-1,000 metres (~3,280 ft): 27.3 s

    Fuel Consumption
        Urban: 8.1 litres/100 km
        Extra-urban: 5.6 litres/100 km
        Combined: 6.5 litres/100 km
        CO2 Emissions: Total 172 g/km
        Emission Category: Euro 5