Run Silent, Run Deep


The Audi A3 e-tron Sportback

Posted on August 5th, 2014 by Susanne Roeder & Ian Kuah

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The most outstanding quality of Audi’s A3 e-tron Sportback plug-in hybrid that very quickly becomes apparent to a first time driver is how seamlessly the two disparate halves of its powertrain integrate in real world driving conditions.

Unlike a pure electric car, you hardly have to learn anything new to operate this petrol-electric hybrid, and what you do need to know can be conveyed in a matter of minutes when your dealer hands the car over.

Another positive aspect of the e-tron’s dynamic performance is the way it goes down the road. With springs and dampers uprated to cope with the e-tron’s 320kg of extra weight, its feels even more supple and mature in the way it tackles bumps than a normal A3. 

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The 1.4 TFSI motor has 150hp and 250Nm of torque. The electric motor is rated at 101hp (75kW), with 330Nm of torque. However, as the power delivery curves are not additive, the total system power works out at 204hp, with a total system torque of 350Nm. The compact electric motor weighs 34kg and sits between the 100kg transversely-mounted internal combustion engine and the six-speed S-tronic gearbox with integrated drive de-coupler.

The presence of this de-coupling clutch is significant as one of the issues with electric and hybrid cars is the un-natural feeling of strong deceleration when you take your foot off the throttle.

This is caused by the strong braking effect of an electric motor when it is not delivering power. However, it turns out that coasting is a more efficient use of kinetic energy than brake recuperation, so this solution kills two birds with one stone.

The fact that an electric motor develops its peak torque at zero revs gives the e-tron very good low-end punch, and this is reflected in its 0-60km/h time of 4.9 sec. The 0-100km/h time of 7.6 sec is not quite hot hatch beating, but is more than adequate. Top speed in petrol mode is 222km/h, and you can run at up to 130km/h in e-mode, which corresponds to the highway speed limit in most European countries.

If performance is good, economy is outstanding, and Audi claim the A3 e-tron will do 1.5 L/100km or 188 mpg in old money, with emissions a paltry 35g/km. In real world driving on our test route, which included everything from the urban grind in Vienna to motorways, we saw an average of 4.3L/100km or 65.7mpg, which is still very impressive.

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The e-tron’s ability to run in pure electric (EV) mode for 50km on a full charge means that for most people, the daily commute with zero emissions is taken care of. The fuel tank takes 40 litres, which is good for 650km. Using both power modes in tandem, the car has a potential range of up to 890km.

The 18 km drive from Vienna airport to our hotel was well within the A3 e-tron’s EV range, and it was actually very pleasant to cover this distance with a total lack of mechanical noise and vibration.

While you can certainly hear the stereo better at a lower volume, this also implies that a base car with low chassis rolling noise is desirable. Thankfully the A3 also delivers in this respect.

Our test cars were pre-production examples, and while there will be some further software updates before the A3 e-tron goes on sale in the late summer, the cars we drove are by and large what a paying customer can expect.

The standard Audi A3 1.4 TFSI Sportback weighs 1,230kg. With its battery pack and other hybrid componentry, the e-tron tips the scales at 1,540kg (DIN), and its 57/43% weight distribution makes the e-tron slightly less nose heavy than the 60/40% of an A3 TDI. Its electric power steering has a nice weighting for easy low speed manoeuvring, with a ratio that also made easy work of the mountain roads in the hills above Vienna.

The fact that the 125kg, 8.8 kWh Lithium Ion battery sits right down low on the floor just in front of the rear axle is of huge benefit to the handling balance of a normally nose-heavy front-wheel-drive hatchback.

Shod with grippy 225/45R17 tyres, the e-tron exhibited less understeer in bends, and less perceived weight transfer under acceleration and braking than a normal A3.

Another advantage of placing the battery pack in this position is realised in luggage carry ability, which remains unchanged from the 280-litres of an A3 quattro, expanding to 1,120-litres with the rear seats folded flat.

The floorpan is derived from the A3 quattro, with some new sheet metal in strategic places like the battery storage compartment. The centre tunnel of the quattro floorpan is required for mechanical packaging reasons, since the area where the propeller shaft and exhaust system are normally found now contains a long, triangular-section centre silencer.

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From A1 to A8, consistently good build quality is an Audi strong suit, and the A3 impresses from the moment you open a door and step inside. The class leading fit and finish of its cabin sets the class benchmark, giving the impression that this compact Audi is a smaller rather than a cheaper version of their larger models. 

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In the cabin, everything is exactly as you would find it in a normal A3 apart from the instrument cluster where a power meter replaces the rev counter. This indicates Charge, Efficiency, and Power Boost from the batteries. In energy recuperation mode, coasting and braking both send power to the batteries.

The familiar pop-up MMI screen on the dashboard has the usual items like sat-nav, but an extra function controlled from a button on the dashboard allows the driver to choose the running mode for the vehicle.

The first of these is EV (Electric Drive) where the e-tron runs in purely electric mode, drawing power from the batteries, as I tested on the drive from the airport to the hotel. The car’s default mode on start up is EV unless the battery is depleted.

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The second mode is Hybrid Auto. In this setting, the computer decides when to run the petrol or electric motors or both for optimum efficiency. So if the batteries are getting low, the internal combustion motor will cut in to charge the batteries until they are at the point where efficient running on electric power is feasible again.

In Hybrid Hold mode, the aim is to retain battery charge, so the computer will do its utmost to use the petrol motor and coasting and braking to charge the batteries to be used later. The final mode is Hybrid Charge, where the system will try to increase the battery charge as much as possible using extra regenerative braking and the petrol engine as a generator.

If the car is running on battery power initially in very cold weather there is the issue of engine wear on the internal combustion engine if it is suddenly engaged in kick down when stone cold. Because of this, special piston rings and cylinder liners are used, and a sensor monitors oil quality.

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The A3 e-tron Sportback has three independent cooling systems. The first is the normal water-cooling system for the internal combustion motor. The second is the water-cooled charge-air intercooler for the forced aspiration component of this motor.

Last but not least is the cooling system for the batteries and power electronics. This uses the heat exchange component of the vehicles air-conditioning to maintain the batteries within their rated operating temperature envelope.

That means the a/c system is always on, which is an advantage as most people are not aware of the fact that switching off the a/c in winter is bad since the small amount of lubricating oil circulating with the coolant gas keeps the rubber seals in the system from drying out. Also, as air-conditioning extracts humidity form the air, it keeps your windows clear when it is cold and damp or raining.

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An A3 e-tron App for smart phone junkies allows you to access your travel data information like average fuel consumption, distance and driving time. It also tells you your battery charge status and range.

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And when the car is connected to the mains charger, you can programme the air-conditioning to pre-heat or pre-cool the car’s interior, so you do not have to draw power from the battery for this task once you are driving. Mains charging time is 3 hours 45 min on a normal household supply, dropping to 2 hrs 15 min if you have a 16 Amp socket.

The Audi A3 e-tron goes on sale in Europe this summer, and in China in 2015. Audi will offer an A6 e-tron LWB in China in 2016, as a joint-venture project using many locally sourced components, and Q7 e-tron will follow.

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At 37,900-euro (in Germany) Audi A3 e-tron Sportback goes head-to-head with the likes of the Toyota Prius plug-in Hybrid, which it decisively outpoints on driving dynamics, prestige and build quality. It is as large a car as most people need for their daily commute, and is a real pleasure to drive.

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