Les A3 g-Tron et e-Tron d'Audi à Genève 2013 (CPA)

The Audi A3 Sportback e-tron

A driving range of about 50 kilometers (31.07 miles) in electric mode

Total range of 940 kilometers

System power 150 kW (204 hp); top speed 222 km/h (137.94 mph)

Audi is working intently to electrify the drivetrain using plug-in hybrid technology. The brand with the four rings is showing the Audi A3 Sportback e-tron at the 2013 Geneva Motor Show. With 150 kW (204 hp) of system power and 350 Nm (258.15 lb-ft) of system torque, sporty performance is guaranteed.

The A3 Sportback e-tron is a true Audi. It sprints from 0 to 100 km/h (62.14 mph) in 7.6 seconds on its way to a top speed of 222 km/h (137.94 mph). According to the ECE standard for plug-in hybrid automobiles, the five-door model consumes on average just 1.5 liters of fuel per 100 km (156.81 US mpg), which corresponds to CO2 emissions of 35 grams per km (56.33 g/mile). In purely electric mode, the Audi A3 Sportback e-tron achieves a top speed of 130 km/h (80.78 mph) with a range of up to 50 km (31.07 miles).

The Audi A3 Sportback e-tron uses the highly efficient concept of a parallel hybrid. The combustion engine is a modified 1.4 TFSI, which develops 110 kW (150 hp) and 250 Nm (184.39 lb-ft) of torque. The TFSI operates in tandem with an electric motor that generates 75 kW and 330 Nm (243.40 lb-ft) of power.

The disc-shaped electric motor is integrated into a newly designed six-speed e-S tronic, which transfers the power to the front wheels. The two powerplants complement each other. The electric motor develops peak torque from start to around 2,000 rpm, and the TFSI's maximum pulling power is available in a range from1,750 to 4,000 rpm.

The Audi A3 Sportback e-tron's energy store is a lithium-ion battery system installed in a space-efficient, crash-protected location in the floor, beneath the rear bench seat. The high-voltage battery, inside a housing made mainly from aluminum, has a capacity of 8.8 kWh. It comprises eight modules with a total of 96 cells.

A liquid cooling system with its own low-temperature circuit keeps the battery in the optimum temperature range. This sophisticated technology is key to the power and stamina of the electric drive unit, which remains available at low ambient temperatures.

The power electronics are housed in the engine compartment of the Audi A3 Sportback e-tron. These convert the direct current from the battery into alternating current to power the motor. The compact unit, with integral DC-DC converter to supply the 12V electrical system shares the same cooling circuit as the battery and charging device.

The charging connection is located behind the four rings in the radiator grille; the charging socket, like the TFSI engine, sports an e-tron badge. The high-voltage battery can be fully charged in around two and a half hours with a 3.6 kW charger. All relevant components within the high-voltage network of the A3 Sportback e-tron have no conductive connections to other parts of the vehicle. In the event of the belt tensioners or airbags being activated in an accident, the system is immediately disconnected from the power supply. The air conditioning compressor has a high-voltage electric drive; an electric auxiliary heater supports the heating function for the interior.

Energy recovery during braking: electrified brake servo
The vacuum brake servo has an additional supply connection served by an electric vacuum pump. The hybrid management is tuned responsively with the electric motor. Up to moderate braking forces the powerful electric motor, now operating as an alternator, supplies most of the retardation and recovers much of the energy expended so that it can be channeled back into the high-voltage battery. The wheel brakes only become active if the driver presses the pedal more forcefully.

The Audi A3 Sportback e-tron can be driven with just the combustion engine, just the electric drive or in hybrid mode. Even in electric mode it offers powerful acceleration without the need to engage the TFSI. The driver can choose to have both powerplants active at the same time ("boosting"). When the driver lets up on the accelerator, they both deactivate temporarily ("gliding"). In this way, engine braking torque is eliminated and efficiency increases.

Three driving programs are selected using the EV button and the e-tron's selector lever. The EV characteristic map covers the electric mode; the D program makes the A3 Sportback e-tron run especially efficiently, and in the S plane it is notably sporty.

The Audi A3 Sportback e-tron display concept supplies precise information of the drivetrain status. The powermeter in the instrument cluster replaces the conventional rev counter and shows overall system power. The instrument cluster also includes a charge status display for the battery. The driver information system's color display and the MMI navigation monitor indicate the power flows in the drivetrain, the operating ranges and the consumption figures for electricity and gasoline.

Audi is planning a whole portfolio of new online services for its electrified vehicles under its Audi connect umbrella policy. These will enable the driver to activate and monitor a whole raft of functions such as charging processes and pre-conditioning of the interior climate conveniently from their smart phone.

Sporty elegance: the interior
The ergonomic interior of the A3 Sportback e-tron has an uncompromisingly high-quality finish. The interior is finished in Cloudy Gray, with contrasting stitching highlighting the S sport seats. The door sill trims are in aluminum and display e-tron logos; there are also e-tron badges on the gear knob and steering wheel. The trunk capacity is 280 liters (9.89 cubic ft); folding down the rear seats increases this to around 1,000 liters (35.31 cubic ft).

With its Misano Red paint finish, the Audi A3 Sportback e-tron declares its sporty character at the very first glance. Its wheels have the characteristic e-tron design, with a 15-spoke look that evokes turbine blades. The chrome horizontal struts in the single-frame grille and air intake grilles have three-dimensional undulating profiles – another e-tron feature. The rear apron with new diffuser is also specific to the e-tron.

The A3 Sportback e-tron demonstrates its full sporting potential when accelerating, sprinting and cornering at high speed. Its on-road performance is based on its sophisticated chassis, coupled with a low weight for a plug-in hybrid, despite its full range of equipment. Standard features include xenon plus headlights, convenient access, a panoramic tilting sunroof, a lighting package, the driving dynamics system Audi drive select, and MMI radio with extending monitor.

At the Geneva Motor Show, the Audi A3 Sportback e-tron will provide a realistic glimpse into the future of mobility as Audi is planning it. The electrification of the drivetrain, above all using plug-in technology, plays a defining role in the strategy of the brand.

The new Audi A3 Sportback g-tron

The new A3 Sportback g-tron is powered by the CO2-neutral Audi e-gas

CO2 emissions of 30 grams per kilometer (48.28 g/mile)

Total range of 1300 km (807.78 miles)

Audi is taking a large step towards sustainable mobility with the A3 Sportback g-tron. The compact five-door car, due to make its debut at the end of the year, is powered by the CO2-neutral fuel Audi e-gas. The fuel will be produced in the power-to-gas plant in Werlte, Germany. This new car innovatively combines ecological balance, economy and high-tech solutions.

The Audi A3 Sportback g-tron comes with the full gamut of Audi's technology expertise – from ultra-lightweight technology, and infotainment, to driver assistance systems. But first and foremost it showcases state-of-the-art CNG drive technology, starting with the fuel storage. Its two tanks under the luggage compartment floor can each hold seven kilograms (15.43 lb) of CNG at a maximum 200 bar pressure. In tune with the ultra-lightweight construction concept, each tank weighs 27 kilograms (59.52 lb) less than its conventional counterpart.

The tanks consist of a new type of matrix. The inner layer consists of gas-impermeable polyamide polymer, while a second layer of carbon fiber-reinforced polymer (CFRP) gives the tank its extremely high strength; a third layer of glass fiber reinforced polymer (GFRP) provides rugged protection against damage from the outside. High-strength epoxy resin is used to bind the fiber reinforced materials.

A second highlight of the Audi A3 Sportback g-tron is its electronic gas pressure regulator. This compact and lightweight component reduces the high pressure of the gas flowing from the cylinders down to around five to nine bar in two stages.

It ensures that the right pressure is always present in the gas rail and at the injector valves – low pressure for efficient driving in the lower speed range, and higher when the driver calls for more power and torque.

If the pressure in the tank drops below ten bar, the engine management system automatically switches over to gasoline operation. The Audi A3 Sportback g-tron is fully bivalent, i.e. its performance figures are identical in CNG and gasoline modes.

CNG provides a range – based on standard fuel consumption – of around 400 km (248.55 miles), with gasoline providing another 900 km (559.23 miles) if necessary; the total range is approximately on a par with an Audi TDI. Two displays in the instrument cluster provide the driver with up-to-date information on the fuel level in each of the tanks. The driver information system also displays the current fuel consumption based on the particular operating mode.

The two filler necks are placed under a common fuel flap. After refueling, and whenever it is very cold, the engine is started with gasoline initially, then it is switched over to natural gas as quickly as possible.

The engine is based on the new 1.4 TFSI. Key modifications relate to the cylinder head, turbocharging, injection system, and the catalytic converter. Developing 81 kW (110 hp) and 200 Nm of torque, the Audi A3 Sportback g-tron has a top speed of 190 km/h (118.06 mph), with 0 to 100 km/h (0 - 62.14 mph) taking eleven seconds. The five-door car consumes on average less than 3.5 kilograms per 100 km of CNG or Audi e-gas – the fuel that is generated from eco-electricity in the Audi e-gas project. CO2 tailpipe emissions are less than 95 grams per km (152.89 g/mile) in gas mode.

The greenhouse gas balance is even more attractive in a well-to-wheel analysis that accounts for all factors from the fuel source to the car's wheels. When the A3 Sportback g-tron is powered by Audi e-gas, no more CO2 is released than was chemically input in its production beforehand – creating a closed loop. When the energy required to build the e-gas facility and wind power generators is included in a comprehensive analysis, CO2 emissions are still less than 30 grams per km (48.28 g/mile).

Buyers of the Audi A3 Sportback g-tron will presumably obtain the e-gas at the public CNG refueling stations via an ecological accounting­ method, similar to the method currently in existence for obtaining eco-electricity.

With the e-gas project, Audi is the first automobile manufacturer to develop an entire chain of sustainable energy carriers. The start of the chain has electricity produced from renewable energy sources; the end products are hydrogen and the synthetic Audi e-gas. Construction of the world's first industrial plant to produce synthetic methane (e-gas) from CO2 and renewable electricity is almost complete in Werlte (Emsland district of Lower Saxony), Germany.

The Audi e-gas plant uses the renewable electricity in the first stage for electrolysis – splitting water into oxygen and hydrogen (Audi e-hydrogen), which could one day power fuel-cell vehicles. Because there is not yet a widespread hydrogen infrastructure, however, the hydrogen is then reacted with CO2 in a methanation plant to produce renewable synthetic methane, or Audi e-gas. Chemically speaking, this e-gas is identical to fossil-based natural gas. As such, it can be distributed to CNG stations via the natural-gas network.

Thanks to the power-to-gas process, the electricity grid and gas network are being linked bidirectionally for the first time. Until now while you could generate electricity from gas, the reverse was not possible. The Audi e-gas plant therefore paves the way for tapping into the natural-gas network with its huge capacity as a storage and transport system for hitherto excess electricity capacity.

The CO2 used in Audi's e-gas plant is a waste ­product from a nearby biogas plant, operated by power utility EWE. The CO2, which would otherwise pollute the atmosphere, is chemically bonded into the fuel at the Audi e-gas plant. The e-gas plant will annually produce about 1,000 metric tons of e-gas and will chemically bind some 2,800 metric tons of CO2. This corresponds roughly to the amount of CO2 that 224,000 beech trees absorb in a year.

The CO2-neutral e-gas from Werlte will power 1,500 new Audi A3 Sportback g-tron vehicles 15,000 kilometers (9,320.57 miles) every year. The power industry can also benefit from Audi's e-gas project, as it addresses the nagging challenge of how to store large quantities of renewable electricity produced from wind turbines and photovoltaic systems efficiently and irrespective of location. The electricity-gas cogeneration technology could significantly foster the expansion of renewable energies.