TheAudi A8 is the newest limo on the block and this is the A8 hybrid which aims to be the greenest in the segment. Shown at the Geneva show for the first time, the A8 hybrid’s drivetrain consists of two propulsion units – a 2.0 TFSI internal combustion engine and an electric motor – that develop a total output of 245 bhp and 480 Nm of torque. This enables a 7.6-second 0-100 km/h time and a top speed of 235 km/h, done in Transporter style coolness.
A hydraulically operated wet clutch links the TFSI with the electric motor (with 45 bhp and 211 Nm), which makes available its grunt from standstill. In the boot lies the Audi’s lithium-ion battery pack, which still leaves 400 litres of luggage space. Subsystems that operate on engine power in a regular car have been modified to run entirely on electric power in the A8 hybrid, such as the air-con compressor, electromechanical steering system and brake booster, all managed by a “pulse control inverter” system. All these will appear in the Audi Q5 hybrid, to be introduced later this year.
This A8 is capable of fully electric-powered driving up to 65 km/h and for a distance “exceeding 2 km”. Normally, both work in tandem but above 65 km/h, the combustion engine propels the car alone, while the electric motor supplies ancillaries and recharges the battery. The TFSI is disconnected from the drivetrain when the driver chooses to coast. The e-motor also functions as a generator to recoup energy from braking and replenish the battery.
Green credentials? The A8 hybrid’s average fuel consumption is 16.1 km/l while CO2 emissions is 144 grams per km. These figures compare very well with the Mercedes-Benz S400 Hybrid, which does 12.7 km/l and 186 g/km. Launched last year, the car from Stuttgart pairs a V6 with electric motors for a combined 299 bhp/385 Nm, and was the first production hybrid to use lithium ion batteries
