Porsche Mission E electric saloon revealed at Frankfurt

It also allows the new four-seater to run at its top speed of over 155km/h for extended periods, according to Porsche.

A retractable body element within the front left wing provides access to the charging port for what is described as the Porsche Turbo Charging system. It uses an industry first 800 volt process – doubling the charging voltage used by the Tesla and its Supercharger system.

As a result, Porsche claims the Mission E’s battery can be charged to 80 per cent of capacity, a level which Hatz says provides up to 249 miles of range, in just 15 minutes – or less than half the time taken by existing electric cars. The 800 volt system also permits a lighter wiring harness with smaller gauge copper wires.

By mounting the liquid-cooled battery low down in the floor wholly within the wheelbase, Porsche says it has succeeded in providing the Mission E with a centre of gravity similar to that of the recently discontinued 918 Spyder.  The lithium-ion unit, which draws on the cell technology also used by Audi with its e-tron quattro concept, is cooled in a process similar to that used by the 919 Hybrid race car, making it suitable, according to Porsche, for extended race track use.

All-new platform

The Mission E is based on a newly developed platform conceived specifically around its electric drive system. “We have taken a whole new direction with the structure. There’s no need for a traditional centre tunnel, for example, and this has been factored in to the design,” reveals Hatz.

The floorpan is made from aluminium, high-strength steel and carbon-fibre reinforced plastic – a combination Porsche says will be reflected on the production version tentatively planned to appear in 2018. Significantly, the adoption of a bespoke platform rules out petrol, diesel or hybrid variants of the new car. “It is a standalone electric car,” declares Hatz, putting to rest speculation that the new concept also holds clues to a long-mooted saloon model to go up against the Audi A6, BMW 5-series, Jaguar XF and Mercedes-Benz E-class.

Hatz doesn’t categorically rule out a sub-Panamera saloon, but he indicates such a would require a different platform and floorpan structure to the Mission E.

Hints of new Panamera

Various elements of the concept car’s chassis, including the suspension, have been sourced from the second-generation Panamera, due out in 2016. Details still remain scarce, though Porsche confirms the use of four-wheel steering – a development now available across the 911 line-up.  The 21-inch front and 22-inch rear wheels make use of the centre locking mechanisms first used by the 911 GT3.

Reiterating the significance of the engineering project behind its development, Autocar’s 2015 man of the year, said: “We are deadly serious about this car. It is not just a concept, but at clear look at the future of Porsche. The implications to the brand are as important as those when the 911 was created over 50 years ago.”

The four-door Mission E was styled by a small team led by Porsche design boss, Michael Mauer. The former Mercedes-Benz, Saab and General Motors designer has been responsible for a range of critically acclaimed Porsche concept cars in recent years, including the original 918 Spyder concept wheeled out at the 2010 Geneva motor show.

The new car combines the fundamental look of traditional rear engine Porsche models up front together with the stretched proportions of the German car maker’s more modern front end offerings, providing the Mission E with a wonderfully balanced appearance that’s further enhanced by a terrifically strong stance.

The smooth surfacing treatment and exquisite detailing throughout endows the new car with puristic look in keeping with the timeless appeal of all great classic Porsche models. However, there is also evidence of progressiveness in the way Porsche also eschewed traditional headlamps for distinctive LED assemblies boasting the four point graphic of recent models and used small cameras mounted in the front wings, with images projected on to the lower corners of the windscreen, in place of traditional rear view mirrors.

Among those involved in developing the arresting exterior of the new concept was Mitja Borkert, the head of Porsche’s advanced design department largely credited with developing the svelte lines of the earlier Panamera Grand Turismo.

New style, familiar feel

At 4850mm in length, 1990mm in width and 1300mm in height, the Mission E is 165mm shorter, 60mm wider and a significant 120mm lower than Porsche's existing saloon, the Panamera. By comparison, the Tesla Model S stretches to 4975mm in length, 1965mm in width and 1435mm in width.

Inside, the concept provides accommodation for up to four on individual seats featuring a heavily structured design, ultra thin back rests and integrated headrests both front and rear. There are also two luggage compartments – one up front under the bonnet and another smaller one at rear beneath the fixed rear window.

Despite boasting a more heavily raked windscreen than its legendary stablemate, the driving position and front seat height is similar to that of the 911. “We wanted to provide it with a familiar Porsche feel,” says Ivo van Hulten, the interior designer.

A highly contemporary looking dashboard receives a free standing five-dial instrument binnacle featuring an eye tracking function activated by a button on a three-spoke steering wheel. When activated, the three-dimensional display automatically adjusts to suit the position of the driver, providing a tailor made environment in which all relevant information is set perfectly in the line of sight. Additionally, a holographic display extends into the passenger’s side of the car, providing information in three-dimensional graphics.

The production version of the Mission E must occupy a regular slot in Porsche's line-up, said project chief Stefan Weckbach: “The question is whether there will just be battery car enthusiasts in four or five years’ time, or will there just be people who want a nice-performing car?”

The product planning case for the 4.8-metre-long Mission E is based around the assumption that electric cars will be mainstream models, which explains why theMission E is sized to sit below the Cayenne and Panamera.

“We don’t want to substitute our Panamera or SUVs, so we have targeted a smaller segment,” said Weckbach.

Because of that and its electric-only make-up, the car is being designed from the ground up. Only minor modules will be shared with the new Volkswagen Group MSB platform, which Porsche is developing for the next-gen Panamera and Bentley Continental range. The battery will be co-developed with Audi’s e-tron quattro, which also appeared at Frankfurt.