Efficiency potential can be exploited even more consistently with an intelligent combination of tried-and-tested technologies and alternative fuels. For example, the Audi A3 Sportback g-tron is the first Audi production model with a bivalent drive system featuring pioneering TFSI technology with CNG modification.
It is based on the tried-and-tested 1.4 litre 4-cylinder TFSI engine, with the cylinder head, turbocharger, injection system and catalytic converter adapted to the specific properties of natural gas. The natural gas is stored at up to 200 bar in two lightweight, high-pressure tanks at the rear behind the normal petrol tank. They each hold 7 kg of CNG (Compressed Natural Gas). When the 14 kg of highly compressed natural gas is used up and the system pressure drops below 10 bar, the system switches automatically to TFSI operation – without you even noticing.
In pure CNG mode, an Audi model with g-tron technology travels an impressive 400 km with a remarkable low consumption of 3.2 – 3.3 kg CNG/100 km. One kilogram of natural gas contains as much energy as 1.5 litres of petrol. During combustion, CO2 emissions are 25 – 30% less than with petrol. Acceleration and dynamics are not perceptibly impaired. Overall, a range of around 1,300 km is achieved, which is equivalent to the distance between Berlin and Le Mans or Copenhagen and Bern. With its impressive efficiency and long range, g-tron convinces in every respect.
Yet Audi is going one step further and is setting another milestone on the path to consistent CO2-reduced mobility with the Audi e-gas project. Audi e-gas is produced exclusively from renewable resources. Wind energy is used to produce hydrogen through electrolysis, which later reacts with CO2 during methanisation to produce the Audi e-gas. The CO2 used by the Audi e-gas system is the exhaust gas from a biomethane plant operating on organic waste. This means that a particularly environmentally compatible fuel is already being produced, which is virtually identical to fossil natural gas; however, the only CO2 released was bound during the production of Audi e-gas. This creates a closed cycle.
With this complete chain of effective CO2-reducing measures – from the primary energy source of the fuel to the highly efficient vehicles – Audi is demonstrating how exciting sustainability and future mobility technologies can be.