New, more efficient g-tron versions with greater range for the Audi A4 Avant and A5 Sportback

They will be on display at the four-rings stand at the Frankfurt Motor Show next September, and they are sure to attract the attention of all those who do not want to give up sporty driving simply because they care about the environment. Audi offers all of them a more than interesting alternative with its new g-tron versions based on the A4 Avant and A5 Sportback models.

Enjoying sporty driving every day while being environmentally friendly, without having to give up range, is possible. Thanks to their natural gas engines, the new g-tron versions of the Audi A4 Avant and Audi A5 Sportback offer up to 950 kilometres of range —500 of them running on CNG— without the need to stop and recharge batteries or refuel.

Both models have under their respective bonnets the 2.0 TFSI engine producing 125 kW (170 CV), which allows dual use of petrol and compressed natural gas as energy sources, delivering in both cases the maximum torque of 270 Nm needed to enjoy the dynamic conditions required for a sporty and highly rewarding drive.

In the case of the A4 Avant, the g-tron engine, offered in combination with the S-tronic gearbox, needs only 3.8 kilos of gas to cover 100 km. In petrol mode, this family saloon consumes only 5.5 l/100 km, with both cases offering low CO2 emissions figures (102 and 126 g/km). On the A5 Sportback, consumption and emissions figures in gas mode are identical, while petrol consumption varies by barely a tenth (5.6 l/100 km) without affecting emissions.

The use of compressed natural gas engines also represents an important source of fuel savings, as the price of a kilo of gas is clearly lower than that of a litre of petrol. A kilo of CNG costs around 0.89 euros, compared with 1.43 euros for a litre of petrol at the same filling station. This allows significant savings in fuel consumption, savings that increase thanks to the financial incentives for purchase offered under the MOVEA plan and to the reduced parking rates in surface car parks that councils and local authorities set for this type of vehicle.

This last point, in addition to the possibility of driving in city centres on days with pollution restrictions, is due to the lower emissions these vehicles produce, since the combustion process of CNG is much cleaner than that of any other fossil fuel.

The transition from petrol mode to CNG mode takes place completely automatically and without any need for driver intervention. The car always runs in CNG mode until the pressure in the tank storing it drops below 10 bar (about 0.6 kg). At that point, the engine starts on its own to run as a normal TFSI engine using the petrol stored in its fuel tank. Running exclusively on gas, either model can cover 500 km, to which are added the further 450 km that can be covered thanks to the capacity of the petrol tank.

The gas is stored in a high-strength tank —assembled and tested directly on the model’s production line— made of carbon fibre reinforced polymer (CFRP) composite and installed beneath the rear structure of the car. It stores up to 19 kg of gas at a pressure of 200 bar. The boot capacity of the A4 Avant g-tron is 415 litres and that of the A5 Sportback g-tron is 390 litres.