Audi has previewed its plans for an advanced new electric-powered luxury sedan with the unveiling of the e-tron GT Concept at the 2018 Los Angeles motor show.

Set to see production by the end of 2020, the low-slung four-door is a sister model to the Porsche Taycan, with which it shares an aluminium intensive platform as well as key elements of its electric drivetrain and chassis.

In its most potent form, the new Audi is planned to be fitted with two electric motors developing a combined 434kW together with an electronically controlled four-wheel drive featuring a torque vectoring function to constantly vary the amount of power sent to each individual wheel.

Although billed as a concept, Audi confirms the e-tron GT has already been granted production approval. It also reveals prototypes of the new model are presently undergoing intensive testing under high security at its Ingolstadt-based R&D centre in Germany in preparation for a planned unveiling for the production version less than two years from now.

Billed as one of the fastest accelerating road-going Audi models yet, it is earmarked to be the third in a range of twelve new electric powered e-tron models planned for sale by the German car maker by 2025, following the recently unveiled e-tron quattro SUV and next year’s e-tron Sportback crossover.

The basis for the new e-tron GT is the so-called J1 platform developed by Porsche. Originally planned to be used exclusively by the Taycan due out next September, it has been adopted by Audi for the e-tron GT in a move aimed at netting the two Volkswagen Group companies important economies of scale through component sharing as they set about establishing their own individual electric car ranges.

Different in design to C-BEV underpinnings of the e-tron quattro and e-tron Sportback as well as the PPE platform being developed jointly by Audi and Porsche for other future electric powered models, the J1 structure has been conceived expressly to provide a low centre of gravity by housing batteries as low down as possible within the floorpan and featuring a roof made partly from carbon fibre.

In the upcoming Taycan, it contributes to a centre of gravity that is claimed to be 80mm lower than that of the outgoing seventh-generation 911, according to Porsche.

Insiders privy to the definitive production version of the new electric powered Audi say it closely reflects the look established on the e-tron GT Concept, suggesting only minor changes will be made to its appearance before it reaches Chinese showrooms.

To be positioned below the upcoming Porsche Taycan at a price expected to see it compete directly against the Telsa Model S, it builds on the current Audi design lineage with a bold appearance that incorporates various cues from the latest RS5 Sportback, A7 Sportback and R8 in a heavily structured exterior featuring a series of unique styling details described as being reserved exclusively for its new range of e-tron models.

Initially hinted to in a sketch issued to the media during Audi’s annual financial press conference earlier this year, the new model follows the lead of the Porsche Taycan with four conventional front-hinged doors and a sloping boot lid with an active spoiler that deploys at speed to increase downforce - a layout Audi officials confirm to Drive will be carried over to the production version of the new car.

Central to the appearance of the e-tron GT is a new interpretation of Audi’s signature single-frame grille featuring three-dimensional elements and prominent e-tron identification within its lower section, large vertical air ducts within the outer extremities of the front bumper, angular headlamps with distinctive laser beam graphics, a deep cut out within the bonnet and broad-shouldered front fenders housing charging points either side.

Further back, the upmarket liftback receives conventional wing mirrors, frameless doors, sills styled to reflect the housing of a battery low down within the body structure as well as its place of production with red coloured Audi Sport badges, traditional B-pillars within a familiar-for-Audi six-window glasshouse and a heavily rounded roof whose structure is fashioned from carbon fibre and houses a full length glass panel.

It is at the rear, however, where the new Audi concept is said to most closely resemble the production e-tron GT, with broad hunches matching those up front set over the rear wheels, a heavily angled rear window, distinctive OLED tail lamps that form part of a full-width light beam and a multi-channel diffuser element.

While the concept car on show in Los Angeles rides on showcase 22-inch wheels shod with 285/30 profile tyres, the production of the e-tron GT is expected to feature more modest 20-inch rims with larger aspect ratio rubber as standard.

At 4960mm in length, 1960mm in width and 1380mm in height, Audi’s third dedicated electric powered model is 9mm shorter, 52mm wider and 42mm lower than the existing second-generation A7 Sportback launched earlier this year. It also rides on a wheelbase that is 26mm shorter than its combustion engine sibling at 2900mm.

By comparison, the Tesla Model S measures 4979mm in length, 1964mm in width and 1445mm in height, while based around a 2960mm wheelbase.

Inside, the e-tron GT receives a uniquely styled interior featuring a layered dashboard that wraps around into the top of the front door linings. It houses a multi-function steering wheel with a stop/stop button within the right-hand side spoke and two main digital displays - one for the instruments and the other for the infotainment functions. A further digital display sits below the infotainment display housing the air conditioning functions.

The front seats feature integrated headrests and are divided by a wide centre console set atop a central tunnel that runs back through the middle of the cabin. As in the Taycan, there are cut outs within the floor at the rear to free up foot space for occupants accommodated on individual rear seats.

In another similarity to its Porsche sibling, the e-tron GT boasts two separate luggage compartments - one up front offering a capacity of 100 litres and a larger one at the rear with up to 450 litres. The combined 550-litre capacity is 15-litres more than that offered by the latest A7 Sportback.

Power for the e-tron GT comes from a pair of synchronous electric motors - one mounted up front and the other sited at the rear in a move aimed at providing the new four-door with the best possible front-to-rear weight distribution.

The two motors deliver a combined system output of 434kW (590-hp). An electronic quattro four-wheel drive system is used to constantly vary the amount of drive delivered to the front and rear axles as well as between the left-hand side and right-hand side wheels dependent on prevailing grip levels and yaw rates.

Computer simulations for the new low slung sedan point to a 0-100km/h time of just 3.5 seconds - a time that would make it second fastest accelerating Audi model behind the R8 if they hold true. To underline its heady performance potential, Ingolstadt officials also suggest the production version will deliver a 0-200km/h time of “just over 12 seconds”.

As Porsche has recently claimed with the Taycan, Audi says the e-tron GT will be able to replicate these times acceleration figures several times in succession due what it describes as a sophisticated cooling strategy that aims to keep the battery in an optimum temperature range even after repeated rapid depletion of energy.

Although Audi says it could theoretically go faster with appropriate gearing, the most powerful production version of the e-tron GT will be limited to 240km/h (124mph) in the interest of range, which is put at 400km under the recently introduced WLTP test cycle procedure.

Audi officials on hand at the unveiling of the e-tron GT Concept in Los Angeles said the new five-door would be developed into a series of production models. This suggests that, like the Telsa Model S, it will eventually be sold with a range of different power outputs, with the 434kW figure likely to apply to the range-topping model only.

Electrical energy used to power the e-tron GT’s electric motors is provided by a 90kWh lithium-ion battery. It uses individual cells supplied by Korean company LG Chem and is housed wholly within the floor structure in a move, Audi claims, provides its third dedicated electric model with a centre of gravity comparable to that of the mid-engined R8.

While described as being the same battery as that earmarked for the upcoming Porsche Taycan, Audi says the lithium-ion unit of the e-tron GT will be combined with a unique power electronics system that will allow it to offer class-leading energy recuperation. It incorporates an electro-hydraulic brake control system similar to that seen on the new e-tron quattro SUV to provide differing recuperation modes that can be selected via the steering wheel mounted shift paddles.

Benefitting from the lead taken by Porsche with the Taycan, Audi also confirms the e-tron GT will offer 800-volt charging. This will allows recharging to 80 per cent of battery capacity in 20 minutes. It will also be able to be charged at lower voltages and, as a likely option on the upcoming production version, via a wireless charging function that uses contactless induction within an alternating magnetic field to top of the battery without the need to plug it in.

The chassis that underpins the new Audi is described as being similar in design to that used by the Taycan, although Ingolstadt officials say it will receive its own unique tuning in a bid to provide the e-tron GT with characteristic driving traits. Included among the innovations incorporated on the new car is a four-wheel steering system.

The production version of the e-tron GT will be assembled by Audi Sport at its Böllinger Höfe facility located on the outskirts of Neckarsulm in Germany - the same site responsible for the assembly of the mid-engined R8. Planned production numbers are yet to be revealed, though insiders hint at a capacity of up to 20,000 cars during the first full year, with scope for added production volume should sales demand warrant it.

While production of the new electric-powered Audi model is planned to kick off in late 2020, officials confirm the first deliveries of the e-tron GT are not planned to get underway until early 2021.