Browse over 9,000 car reviews

Sorry, there are no cars that match your search

Audi e-tron technology: How does it work?

The next EV revolution is here – and you're going to have to really know your cars to spot the difference between electric motion and fossil fuel power.

It looks like a normal Audi SUV... but it's like nothing you've ever driven.

One of the stumbling blocks of the green car movement has been – let's face it – the fact that carmakers think we want something that either resembles a Speed Racer, or shows we're keen to shout out our green credentials.

Er, no.

The next EV revolution is here – and you're going to have to really know your cars to spot the difference between electric motion and fossil fuel power. Until it starts up, of course.

Audi has taken the road less radical with its new e-tron – on the outside, that is. At twenty paces – even at five paces -  it looks a lot like a Q5, but it's quite unlike any SUV that Audi has made before. Let's have a closer look.

Exterior and design

There was a great deal of internal debate about the actual form that Audi's first EV would take, according to Audi's COO of technical operations, Ulrich Widmann.

"it was a big discussion," he smiled. "A sedan is always in favour but not with the usage so a sedan has some customers, and we want to say that Audi brings this contradiction to a solution.

"The demand is on the SUV if you look at the marketplace, so this was the first choice - but we will also provide sedans later on."

He then pointed to the engineering compromises that came with a larger body style.

  • Electric SUV segment lights up as Audi charges in with e-tron. Electric SUV segment lights up as Audi charges in with e-tron.
  • The e-tron, the five-seat, five-door SUV is a fraction longer and a fair bit lower than a Q5. The e-tron, the five-seat, five-door SUV is a fraction longer and a fair bit lower than a Q5.

"The discussion was really [that] the SUV must be the first car, and the SUV should really work in an efficient manner," he said.

That efficiency starts with aerodynamics, and a lot of work went into making sure the e-tron was as slippery as possible. Up to 30 per cent of force from the motors goes into overcoming air resistance, so the more easily the e-tron slips through the air, the better.

The underside, for example, looks like something from a Le Mans racer; a set of panels covers almost every square centimetre of underside, including the rear suspension, and those panels are dimpled like the surface of a golf ball to further calm the airflow under the car.

Vents in the lower front bumper also draw air through the bumper itself before directing it down the side of the car, preventing air from pooling on the bumper and adding drag.

Those fancy mirrors, too, are a designer's fantasy come to life, minimising eddies and turbulence all the way down the side of the car and helping the e-tron achieve its startlingly low drag coefficient of just 0.27. Compare that to, say, a Ford Everest at 0.39, while a Q5 is 0.30.

Powertrain and platform

What's most interesting to me is that Audi has decided to use an existing platform – albeit a pretty new one – to fast-track the e-tron's development time. Using a known quantity means that a lot of the decisions about items like suspension placement and cabin size are framed out for both designers and engineers, and a lot of the components needed to complete the car's basic structure – suspension uprights, for example – are already sorted out.

The 'MLB Evo' chassis is a modified version of the bits under the new A4 and Q5, just to name a couple.

"MLB Evo is our longitudinal platform which we use on a lot of cars now on the marketplace. We enhanced this platform with electric capabilities, so we have all innovations inside this car," says Mr Widmann.

"The platform comes with a lot of modules. One module, for example, is climate control. We used a lot of modules of MLB Evo, but we added also modules that are necessary for electric drivetrains, like the electric motors and the brake system. The suspension and all these things are used from the MLB Evo. So we enhanced the MLB Evo, but the basic [structure] is still MLB Evo."

Those parts include a pair of asynchronous electric motors that are very similar in their construction, though they vary in their output. Both motors also contain a single-speed transmission and two-stage diff in a surprisingly compact unit that mounts low between each pair of wheels.

The front motor provides 125kW, while the rear gives up 140kW. The e-tron has a 49/51 front/rear drive split, and the rear motor will do most of the work at everyday speeds. There's also no magnetic drag when off-throttle, which lowers resistance and saves energy.

Incredibly sophisticated electronics also give the e-tron a box set of new AWD tricks, too. With seven driving modes, the e-tron's motors work with both the braking and suspension controllers to offer millisecond-precise wheel control, no matter the conditions. Torque vectoring, low-grip traction sensing and instant transference of torque to the axle that needs it most are all standard.

There's a handsome level of performance on tap, too, with 265kW and 561Nm of torque, which is instantly available and stays constant across the rev range. Punting the 6.1 seconds from 0-100km/h isn't shabby, but an eight-second Boost mode ratchets things up, bumping power to 300kW and torque to 660Nm.

Brakes and suspension

The e-tron's all-new braking system is particularly tricky, thanks to a three-stage regenerative system that works in seamlessly (according to Audi) with the regular brake system, slowing the car with a combination of electric resistance, which in turns charges the battery.

A paddle behind the wheel allows the driver to choose from one of three levels of regen braking feel; at its maximum, the e-tron can basically be driven just on the throttle pedal, such is the amount of retardation applied by the motors. Up to 30 per cent of the e-tron's range, in fact, comes from regen braking.

The air-sprung suspension, meanwhile, offers variable height control at different speeds, dropping down to improve aerodynamics at speed and raising if terrain gets tricky.

Battery and charging

The 95 kilowatt-per-hour (kWh) battery aboard the e-tron is big; so big, in fact, that Audi uses its cradle as a structural member of the chassis. Mounted to the car at 36 points, the cradle is massively reinforced with box section alloy as well as aluminium sheets, while its 400-plus LG pouch cells are assembled in modules of 12.

Each module is then surrounded with heat-dissipating gel, and the whole unit is water-cooled via a front radiator to stay within 25 to 35 degrees C.

The whole unit can be dropped out of the car, and individual modules can also be accessed if repairs are needed.

"We've also prepared the car for pouch and prismatic cells, so that we can really use the whole available market in battery cells, so we are not dependent on one supplier," says Mr Widmann. "We always look at an open supplier strategy."

Charging the e-tron can occur in a variety of ways; via home charging, charging at public stations and, in the not too distant future, inductive charging (see our story here).

As it stands at the moment, the e-tron can be plugged into a 240-volt wall socket via its own Type 2 plug-equipped charger unit, which will feed it less than three kilowatts of charge, meaning a plus-10 hour recharge time to get it from 10 per cent to 80 per cent.

  • It’s all very nice that companies are talking up their EV futures, but the problem remains: how do we charge them up?
It’s all very nice that companies are talking up their EV futures, but the problem remains: how do we charge them up?
  • The e-tron is one of the latest big-name EVs. The e-tron is one of the latest big-name EVs.

Boosting your home power supply to a three-phase set-up (your stove usually runs three-phase) bumps the output to 11kW and reduces the time to 8.5 hours.

Europe gets a 22kW home charger that can be programmed to top off your e-tron in 4.5 hours using off-peak grid power or even household-produced green energy – but it's not approved for Aussie use yet.

When fast chargers become more widely available, the e-tron can theoretically be charged at 150kW, reducing the charge time to just 30 minutes.

And why 80 per cent? It's the figure where charging times are reduced, in order to protect the battery from over-charging.

Interior and practical stuff.

Inside, the five-seat e-tron feels... like a five-seat Audi SUV. Quality finishes abound, there are plenty of toys and it looks pretty awesome.

Three screens greet the driver, including a new OLED multimedia display and a digital dash, while the centre console features large, deep storage bins – no transmission tunnel, see?

The back seat has decent headroom even for taller drivers, though the sunroof headlining chops into it a bit, and there's a couple of ISOFIX points.

There's a claimed 660 litres of rear boot room, and there's room for a space saver spare under the floor of the cargo area, too. The European specs suggest the e-tron can tow 1800kg, but that's not a confirm for Australia yet.

Safety

Imagine a driver aid, and the e-tron has it (specs, of course, won't be confirmed until next year). Front, side and rear collision assist, adaptive cruise that can slow the car for corners and roundabouts, surround cameras and so much more are part of the e-tron's arsenal.

We'll get to drive the car before the end of the year before its Aussie launch in mid 2019, and based on what we've seen already... we can't wait.

Does the idea of an Audi e-tron charge your batteries? Tell us what you think in the comments below.