For the first time in its history, the Audi A8 adopts a plug-in hybrid drivetrain, capable of covering distances of up to 28.6 miles (measured in accordance with WLTP) under electric propulsion alone and turning a large portion of daily journeys into a locally emissions-free and near-silent driving experience. Its system power of 449PS and system torque of 700 Nm (516.3 lb-ft) ensure impressive vehicle dynamics and a versatile character with complete comfort, while intelligent drive management accurately delivers maximum efficiency through innovations such as freewheeling, recuperation and predictive navigation data.
The A8 L 60 TFSI e quattro, which measures 5.30 metres with its extended wheelbase, will be available to order in the UK later this year, with standard wheelbase models joining the range a few weeks later. First deliveries for both variants will commence soon after in early 2020. They join the Audi A7 Sportback 55 TFSI e quattro, Q5 50 TFSI e quattro and Q5 55 TFSI e quattro SUVs which have already been available on the market since September, signifying the start of the brand’s commitment to its electrification strategy.
“A luxury car is not only defined by the quality of its materials and finish – a sense of calm, comfort and serenity is also integral to the overall experience,” explains Andrew Doyle, Director of Audi UK. “Which is why, with its near-silent, emissions-free driving mode, the A8 TFSI e raises the bar even higher in terms of refinement, even by the exceptional standards already set by the more familiar versions. It is a highly appropriate new addition to the A8 model line which makes perfect sense whichever way you look at it.”
Powered by two hearts: efficient combustion engine and powerful electric motor
A 3.0 TFSI generates propulsion in the A8 L 60 TFSI e quattro. The turbocharged V6 direct-injection engine with a petrol particulate filter delivers an output of 250 kW (340 PS) and 500 Nm (368.8 lb-ft) of torque. It is certified according to the latest emission standard Euro 6d temp. A permanently excited synchronous machine (PSM) with a peak output of 100 kW and a peak torque of 350 Nm (258.1 lb-ft) serves as the electric drive. It is integrated together with the clutch in the eight-gear tiptronic, which transmits the power to all four wheels via the quattro permanent all-wheel drive.
The power electronics converts the direct current from the high-voltage battery (HV) into three-phase current to power the electric motor. During recuperation, it functions as an alternator and feeds direct current back to the lithium-ion battery. The battery is positioned underneath the luggage compartment floor and consists of 104 pouch cells which are allocated to eight modules. The HV battery stores 14.1 kWh of energy and delivers a voltage of 385 V. Its cooling circuit is connected to both the coolant circuit for the air conditioning system and the low-temperature circuit, which also incorporates the electric motor and power electronics. In order to further increase energy efficiency, the standard four-zone deluxe automatic air conditioning works with the heat pump, which uses the waste heat of the high-voltage components.
The Audi A8 L 60 TFSI e quattro delivers a system power of 330 kW (449 PS) and 700 Nm (516.3 lb-ft) of torque. This high system torque is already available at 1,250 rpm, which is just above idle speed. When both motors work together in boost mode, the flagship confidently accelerates from zero to 62mph in 4.9 seconds and reaches an electronically governed top speed of 155mph.
In accordance with the NEFZ standard, the plug-in A8 consumes just 2.5 litres of fuel per 100 kilometres. The Audi A8 L 60 TFSI e quattro can drive on electric power up to a speed of 83mph, and its electric cruising range in accordance with the WLTP standard is up to 28.6 miles. In many countries, its owners benefit from tax advantages or communal road privileges such as free parking or driving in the bus lane.
Intelligent drive modes and the updated predictive efficiency assistant
The driving strategy of the plug-in hybrid drive is designed such that drivers of the A8 can cover a large section of their daily journeys on electric power. The “EV” soft key in the lower of the two MMI displays allows them to decide whether and how they want to adjust the interaction of the two motors at any time. The plug-in hybrid luxury saloon starts in “EV” mode, where it drives on purely electric power. The combustion engine is engaged only when the driver depresses the accelerator pedal beyond a specific resistance. The pressure point is variable and based on the power from the electric drive that is currently available.
“Hybrid” mode offers two operating modes: “Auto” and “Hold”. In “Auto” mode, the predictive operating strategy is activated automatically when route guidance is started in the MMI navigation plus (standard equipment). In addition, the battery charge is spread intelligently and optimally along the route, with large electric portions in the city and in stop-and-go traffic. Generally speaking, the predictive operating strategy endeavours to drive as far as possible on electric power and to use the available battery charge completely by the time the destination is reached.
“Hold” mode pursues a different strategy: Here, the available charge state of the battery is kept at the current level with just minimal fluctuations by means of recuperation and by shifting the load point, i.e. with targeted adjustments to the management of the 3.0 TFSI.
Following a long-distance journey that is driven the conventional way, for example, this allows the subsequent urban drive to be covered on purely electric power, i.e. without emissions and in near-silence.
The operating strategy of the Audi A8 L 60 TFSI e quattro uses various pieces of data to plan the management of the drives. The main focus here is always on optimising ride comfort and energy consumption, as well as keeping CO2 emissions to a minimum. When it comes to planning long-distance journeys, the strategy takes the length and profile of the route as well as online traffic information and the driver’s driving style into account. In the short-term forecast, the standard predictive efficiency assist (PEA) system contributes information from the immediate environment taken from the navigation data, for example speed limits, types of roads and uphill and downhill gradients. The data from the camera and radar that monitor the traffic ahead is also included here.
The phases in which the driver takes their foot off the accelerator pedal are also important for the efficiency of the Audi A8 L 60 TFSI e quattro. The PEA takes over the regulation in such situations. In addition to the navigation data, it also takes the distance to the car in front into account and then decides between freewheeling with the engine switched off and coasting recuperation, i.e. the recovery of kinetic energy and its conversion into electric energy. The Audi flagship can recover up to 25 kW of power through coasting recuperation.
The electric motor also performs all light and medium brake operations up to 0.3 g, which make up more than 90 percent of all brake operations in everyday customer driving. It only works together with the hydraulic wheel brakes in case of heavier decelerations. Thanks to sophisticated fine tuning, the transition, also known as “blending,” between the electric and hydraulic brakes is virtually imperceptible; the brake pedal can always be modulated precisely and provides good feedback. The Audi A8 L 60 TFSI e quattro achieves up to 80 kW of recuperation power while braking.
When the adaptive cruise control (ACC) is active, the PEA assists the driver not only with decelerating but also with fuel-efficient acceleration. If the ACC is switched off, the driver receives prompts that indicate when it would be sensible to take their foot off the right-hand pedal. The driver feels an impulse in the active accelerator pedal and sees information displayed in the Audi virtual cockpit and on the head-up display. Detailed symbols, e.g. for intersections, town signs and traffic driving in front, explain the reason for the reduction in speed.
In the Audi virtual cockpit and on the display of the standard operating system MMI touch response, the driver can view a variety of information on electric driving: power meter, range and the current energy flows of the two drive units. As the central display element, the power meter provides information on the maximum electric performance as well as coasting or braking recuperation, for example.
In addition to the “EV” soft key, the driver of the A8 L 60 TFSI e quattro has a second way of influencing the ride character: the Audi drive select system. With the “comfort,” “efficiency,” “auto,” and “dynamic” modes, the driver can select the setup of the drive, air suspension and steering. Depending on the settings, the way in which the drives work together changes when the driver depresses the accelerator pedal. When the selector lever is in position “S,” the electric motor assists the 3.0 TFSI with a very pronounced boost function to increase dynamics and agility. In this case, freewheeling in overrun mode is blocked; the electric motor thus recuperates whenever the foot is taken off the right-hand pedal.
Sound for greater safety: the acoustic vehicle alerting system
The Audi A8 L 60 TFSI e quattro is equipped with a synthetic e-sound as standard to alert pedestrians and cyclists in city traffic. In accordance with the EU guidelines, the acoustic vehicle alerting system (AVAS) can be heard clearly up to 12mph and gradually fades out as the speed increases. The sound is generated by a small electronics box and output by a loudspeaker in the right wheel arch.
Charge management and pre-entry climate control from the couch: the myAudi app
The standard equipment of the large plug-in hybrid saloon includes what is known as a mode 3 cable for public charging points. The myAudi app allows customers with an Audi A8 L 60 TFSI e quattro to use services from the Audi connect offer on their smartphones. They can also check the battery and range status, start the charging process, program the charge timer and view the charge and consumption statistics. Charging stations are shown both in the myAudi app and in the MMI navigation plus in the car. Another function in the A8 plug-in hybrid version is pre-entry climate control before setting off. The electric compressor of the air conditioning system and the heater booster in the car use power from the high-voltage battery or the socket to heat or cool the interior. And there’s more: The customer can use the pre-entry climate control to activate the steering wheel, seat, mirror and front and rear window heaters as well as seat ventilation to suit their individual requirements via the myAudi app, a timer in the vehicle or the vehicle key.
Specific design details and state-of-the-art equipment
The elegantly flowing exterior design of the product line is complemented by subtle specific design elements in the Audi A8 L 60 TFSI e quattro. The most eye-catching distinctive feature of the luxury saloon with plug-in hybrid drive is a light signature that is based on the Audi e-tron with purely electric drive. There are five horizontal daytime running light segments on the outer edges of the lateral air inlets in the front bumper that form a characteristic signature. There is also a chrome trim on the front bumper and chrome inlays in the door handles. The rear end is accentuated by a continuous diffuser insert and chrome clasp.
The spacious interior of the Audi A8 L 60 TFSI e quattro conveys the relaxed atmosphere of a luxurious lounge. When it comes to equipment, the possibilities are virtually unlimited. The most luxurious seat is on the passenger side in the rear, which is available with an optional relaxation seat with a variety of settings and a heated footrest with a foot massage function. Audi provides more than 30 driver assist systems for the plug-in hybrid saloon which are divided into the City and Tour packages. Lighting options range up to HD matrix LED headlights with Audi laser light and OLED rear lights.
*Article Source http://www.audimedia.co.uk