The luxurious new four-door is expected to be called A9 e-tron and will share much of its technology with the upcoming Q6 e-tron SUV.
The A9 e-tron will have a range of up to 500km (311 miles) between recharging. It is also due to have level four autonomous driving technology — one step up from that used in next year’s new A8.
“By 2020 we will have three EVs in the line-up,” said Stadler. “We’ll start with the production version of the e-tron quattro concept car, which will have a range of up to 500km. By 2025, 25% of our line-up will be battery-driven models.”
Although Stadler is yet to name the A9 e-tron officially, he describes the big electric saloon as being “as high up as possible, in the A8 segment”.
Under an earlier model strategy, Audi had planned to apply the A9 name to a large, conventionally powered four-door coupé to rival the Mercedes-Benz S-Class Coupé and Bentley Continental GT. However, it has been overlooked in favour of the electric luxury saloon, which will have unique styling and the performance to challenge the Model S.
The starting point for the new Audi is the EV platform showcased by the e-tron quattro concept at last year’s Frankfurt motor show. The predominantly aluminium structure differs in design from the one being developed by VW Group sister company Porsche for the production version of its Mission E concept car, which is also due to go on sale by the end of the decade.
Further similarities between the Q6 e-tron and A9 e-tron are expected in the drivetrain. The Q6 e-tron will use three electric motors — one up front, sending drive to the front wheels, and the remaining two at the rear, acting on the rear wheels.
In the e-tron quattro concept, three electric motors produce a combined 429bhp, with a second, sportier drive mode able to temporarily increase that to 496bhp and lift peak torque to 590lb ft.
Audi R&D boss Stefan Knirsch said he is confident the new electric saloon will deliver a unique driving experience through the use of electric motors and a power electronics package that Audi is developing.
Knirsch said: “Some rivals have gone for a synchronous motor with a high power density but at relatively low revs. There are also asynchronous motors that typically achieve similar power outputs but at much higher revs. From 2018, our electric cars will be equipped with asynchronous motors. We are convinced they offer higher efficiency levels than synchronous motors.”
He also pointed to the tuning of the electric drive system as one key area that will differentiate the driving characteristics of Audi’s EVs from those of rivals.
“You’ll see significant differences in the torque vectoring, the four-wheel drive set-up and the power electronic packages,” he said.
The system being developed for the A9 e-tron sends power to all four wheels via a drive management system, which uses electronic torque vectoring to apportion power between individual rear wheels depending on grip levels. The single-ratio gearbox offers the choice of two modes: Drive and Sport.
As an indicator of performance, Audi says the production version of the e-tron quattro concept will have a 0-62mph time of 4.6sec and a top speed limited to 131mph.