The driver of the Audi A8 hybrid can use a button on the center console or the tiptronic selector lever to choose between three driving programs. The EV characteristic map gives priority to the electric drive; the D mode controls both motors efficiently; and the S mode as well as the touch control gate of the 8‑speed tiptronic are designed for a sporty driving style.
The hybrid manager, a proprietary Audi development, is integrated into the control unit of the 2.0 TFSI and manages the transition between the modes. The Audi A8 can be driven in five different modes. Driving with the combustion engine alone, with the electric drive alone or in hybrid mode is possible, as are recuperation and boosting. None of its European competitors in this segment offer such a broad spectrum.
Both drive sources are deactivated when the vehicle is stationary. In this convenient start/stop mode, the automatic air conditioning remains active – its compressor has a high-voltage electric drive and is supported by a separate auxiliary heater.
Once the driver releases the brake, the Audi A8 hybrid starts rolling. It can drive at up to 100 km/h (62.14 mph) in all-electric mode. At a constant 60 km/h (37.28 mph), it has a range of up to three kilometers (1.86 miles) – enough for most residential areas. Top speed with the electric drive is 100 km/h (62.14 mph) – another best.
The TFSI becomes the power source as soon as the driver accelerates further. In many situations, the engine management system increases the load somewhat in order to operate at the ideal point with respect to fuel consumption. The excess energy flows to the electric motor, which uses it to supply on-board consumers and to recharge the battery. When accelerating quickly, or “boosting,” the electric motor operates together with the TFSI; at full throttle, the full system output is briefly available. The hybrid drive then supplies the propulsion power of a large, naturally aspirated engine, but with far more efficiency.
When the driver releases the accelerator, the electric motor recovers energy and stores it in the lithium-ion battery. In most situations the TFSI is then decoupled from the drive system and does not cause any drag losses. “Gliding” like this is possible up to 160 km/h (99.42 mph). If the driver only brakes slightly, the electric motor performs the deceleration itself; during more forceful braking, the hydraulic braking system is simultaneously activated. A complex control strategy adapts all braking actions to the conditions of electric driving and energy recuperation.
Well informed: the hybrid displays
The Audi A8 hybrid has a display concept on board for making the driving states of the hybrid drive tangible to the driver. A power meter replaces the rev counter in the instrument cluster; its needle indicates the drive’s total output on a scale of 0 to 100 percent. Color segments with green and orange sections show at a glance how efficiently the large sedan is currently operating. An additional instrument displays the charge level of the lithium-ion battery.
At the same time, the energy flow display clearly depicts the current mode of operation and active components of the hybrid drive. It can be called up via the driver information system and the MMI monitor. The large screen shows a bar diagram of the average consumption and presents the amount of energy recovered in five-minute increments.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.