Overall rating:

For some time now, Audi has been making a lot of noise about its alternative fuel programme, e-tron. There's been the concept e-tron Spyder, a fully electric R8 and the A1 e-tron - again, an all-electric concept except this time with a range extender rotary engine. And now we've been given exclusive access to the A5 e-tron quattro. This is more than just a concept though; the bigwigs at Audi actually want to take it into full production.

Key Facts

Pricing: not yet confirmed for production
Engine: 2.0-litre turbocharged petrol engine plus two electric motors
Transmission: four-speed R-Tronic dual-clutch gearbox, quattro four-wheel drive
Body style: two-door coupé
CO₂ emissions: 64g/km
Combined economy: 104mpg
Top speed: 142mph
0-62mph: 5.9 seconds
Power: total maximum of 314bhp

In the Metal:

To the untrained eye, this A5 doesn't appear too different to a bog-standard Audi A5 2.0-litre TFSI quattro. Except this has a specially prepared ultra-light body shell. However, it is the mechanical stuff going on underneath the aluminium and carbon polymer skin that makes it unrecognisable from the car it was derived from.

In short, what Audi has done is to dispose of the prop shaft and then mount an electric motor near the rear axle. With the prop removed the central tunnel becomes an ideal housing unit for the bank of lithium-ion batteries and a specially developed four-speed R-Tronic twin-clutch transmission. A further electric motor has been sited just behind the engine.

When all three work in unison the result is a whopping 314bhp. What all of this means in the real world is a car that handles and performs much like the original A5 before it was given the hybrid treatment. It's hard to ignore the performance figures. It'll reach 62mph in 5.9 seconds and boasts a top speed of 142mph. Putting these impressive numbers to one side, the most astonishing fact is that Audi reckons it will return 104mpg while emitting just 64g/km of CO₂.

Driving it:

By using an existing Audi A5 as a donor vehicle for this project there are few surprises within the cabin. It remains that calm and well laid out place we've become accustomed to expect from the German company. There are a few additional big red buttons that we were told 'not to touch' - they are the master switches for the two electric motors and the electromechanical rear brakes.

The multi-media infotainment system has also been rewired to now give a readout for the onboard computers. It shows the mode of power being used, where the power is being sent and an LED display giving a precise state of energy remaining within the battery cells (of course, if this car ever comes to market these extras will be integrated within the interior or hidden away in software of the engine management system).

The all-wheel drive quattro system hardly notices the missing mechanical link between engine and rear axle. For most of the time, only the front wheels are being driven, the electric motor in the rear cutting in as a supportive measure. The specially developed software is constantly working to manage which wheel requires more power and when it detects extra grip is needed it decides where the torque comes from - either the petrol engine or the electric motor, or both - and then distributes it accordingly. All this happens in less than a blink of an eye and without any type of driver intervention.

Where the development process seems to be lagging behind the rest of technology advancements of this car is the four-speed R-Tronic gearbox. It clunks its way up and down the cogs with little finesse and feels like very much what it is: work-in-progress. Putting these teething problems to one side (Audi has only been working on this car for 18 months), the overall handling performs much like its non-hybrid stable mate. In fact, it's better than that, as the set-up features 'torque vectoring' giving it an agility not seen before in a hybrid car.

Worth Noting

Whenever a car brakes, or accelerates, or suffers from any type of motion there is a build-up of kinetic energy. What Audi has done is to harness as much of this as possible and turn it back into electricity to feed the batteries. This means the A5 e-tron can drive on electric power alone for around 30 miles, albeit limited to 62mph. The batteries are also recharged by the petrol engine, which is managed by an on-board computer, or they can be topped up from a household plug. The batteries take around two hours to fully recharge.

Summary

This may only be a concept, and still early on in its development, but it does show where Audi is going with its hybrid programme. As much as it wants to produce a car that offers the best of both worlds - electric and petrol - it also wants to give the driver a car that can be enjoyed for more than its ability to wave an eco banner. And if we are to believe Audi - and we have no reason not to - then expect to see the A5 e-tron go into full production within the next two years.