Audi bets on new propulsion tech

The Audi pavilion at the 83rd Geneva Motor Show, held earlier this month, filled up with visitors within minutes, as the countdown to the unveiling of its new offerings started.

This year the carmaker chose the A3 to sport new hybrid technology. Two introductions – the A3 Sportback e-tron and the A3 Sportback g-tron – are set to hit the roads during this year. Audi's plan is to take the new technology to bigger models in a phased manner.

“I would say that in the last three years we have increased dramatically the level of experience. We had a fleet car like the Audi A1 E-tron, we designed and engineered a sportscar like the R8 E-tron. By the way, we introduced in the market the hybrid versions of the Q5, A6 and the A8 and we got now to a level of experience where we say we know where we want to go and the E-tron story will be the story of the future. So, the plug-in hybrid technology we’ll see in future cars with Audi,” said Rupert Stadler, chairman, Audi AG in an exclusive interview with Autocar Professional.

A3's new green avatars

The A3 Sportback e-tron delivers 150 kW (204bhp) of system power and 350 Nm (258.15 lb-ft) of system torque. According to the ECE standard for plug-in hybrid automobiles, the five-door model consumes on average 1.5 litres of fuel per 100km, which corresponds to CO2 emissions of 35 grams per km (56.33 g/mile). In purely electric mode, the A3 Sportback e-tron achieves a top speed of 130kph with a range of up to 50km. It uses the concept of a parallel hybrid. The combustion engine is a modified 1.4 TFSI, which develops 110 kW (150bhp) 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 electric motor develops peak torque from start to around 2000rpm, and the TFSI’s maximum pulling power is available in a range from1750 to 4000rpm.

The 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 aluminium, has a capacity of 8.8 kWh. It comprises eight modules with a total of 96 cells.

The car can be driven with just the combustion engine, just the electric drive or in hybrid mode. 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.

Gas to the future

The other attraction from Audi was the A3 Sportback g-tron. The compact five-door car, due to make its debut at the end of this year, is powered by a CO2-neutral fuel Audi e-gas. The fuel will be produced in the power-to-gas plant in Werlte, Germany.

The g-tron’s 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 27kg (59.52 lb) less than its conventional counterpart.

A second highlight of the 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. If the pressure in the tank drops below 10 bar, the engine management system automatically switches over to petrol operation. The A3 Sportback g-tron’s performance figures are identical in CNG and petrol modes.



CNG provides a range – based on standard fuel consumption – of around 400km, with petrol providing another 900km, if necessary.The total range is approximately on a par with an Audi TDI.

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 (110bhp) and 200 Nm of torque, the A3 Sportback g-tron has a top speed of 190kph, with 0 to 100kph taking 11 seconds. The five-door car consumes on average less than 3.5kg per 100km 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.

Green and being seen

While the above reflect Audi’s plans in the environment-friendly propulsion technologies, its immediate focus is to achieve the number one luxury car maker’s slot in India, as well as globally. However, its Indian subsidiary, which recorded sales of 9,0003 cars in 2012, will likely to contend with slower market growth this year, following the Union Budget's proposal to raise customs duty on imported cars from 75 percent to 100 percent. Audi currently stands No. 2 in the Indian market.