Audi has revealed prices for its second bespoke electric vehicle, the E-tron Sportback 55, will begin at £79,900 – a £9000 premium over the equivalent version of the standard E-tron.

The firm's new coupé-styled electric SUV is available from launch only in S-Line guise, which includes 21in alloy wheels, LED headlights, adapative air suspension and Audi Sport styling elements as standard. Prices rise to £85,185 for the limited-run Launch Edition, which gains its own set of bespoke sports wheels, contrasting black exterior trim, virtual door mirrors and a range of driver safety systems.

Revealed at the Los Angeles motor show last year, the coupe is the same weight, length and height as the E-tron and from the B-Pillar forward is identical. The lower part of the rear door, bumper and rear lights are also the same, while the obvious difference - the rear roof line - was cut from the A7.

That roofline makes the car slightly more aerodynamic than the E-tron, with a 0.25 Cd compared with the E-tron’s 0.27, giving the Sportback an extra 6.2 miles of range.

Changes from the E-tron include decoupling the front and rear axles so the model can be rear-wheel drive, which adds another 6.2 miles of range. Brake pads have been optimised with stronger springs so there’s no friction when not required, creating an extra 1.9 miles of range. Audi has also swapped two water pumps for battery cooling to one larger one, saving weight and cost and using less energy, which adds up to 1.2 miles of range. The useability of power from the battery has increased by 88% to 91% stage of charge, creating more than 6.2 miles of range.

All in all, the most powerful E-tron Sportback 55 offers 278 miles of range between charges on WLTP testing. A lesser-powered E-tron Sportback 50 does 216 miles but will not be sold in the UK.

While the E-tron Sportback will always have the advantage of a coupe roofline, all other efficiency tweaks will launch in an updated E-tron, revealed late last year.