Audi will be bringing a gas-powered A3 to the Geneva Motor Show. The A3 Sportback g-tron was built together with Audi's new e-gas plant in Werlte, which generates carbon-neutral gas from renewable electricity. The powertrain of the g-tron is composed of two gas tanks and a regular internal combustion engine.
These tanks are able to store e-gas that’s coming from Audi, or regular Compressed Natural Gas (CNG). The Audi's tanks are stored under the boot floor and are capable of holding 7kg of gas each, stored at as much as 200bar. Audi is claiming that the g-tron has a fuel consumption rating on gas of 3.5kg/100 km, offering a gas-only range of 400km (242 miles). When using gas, it means that when full, every fuel tank weighs 27kg lower than a traditional petrol or diesel fuel tank.
The tanks are very strong and light, built from a polyamide polymer and strengthened with carbonfibre-reinforced polymer. When running on gas, the efficiency of the A3 g-tron is boosted by an electronic pressure regulator. It permits low-pressure gas to be combusted in low-speed driving, while at the same time, it permits it to flow at high pressure when higher performance is needed. The petrol engine in the A3 g-tron is based on the 1.4 TFSI that’s in the A3 range and has an output of 108bhp and 147lb ft. According to Audi, the concept is bivalent.
This means that performance is the same regardless of fuel. It can reach a top speed of 118mph and accelerating from zero to 62mph takes 11 seconds. When running on petrol, the engine has a range of 900km (559 miles). The A3 g-tron is included in a bigger project that involves its e-gas facility in Werlte.
It utilizes renewable electricity to deliver gas via water electrolysis, producing hydrogen and oxygen, and through the reaction of the hydrogen with CO2 to deliver synthetic methane which Audi refers to as e-gas. The e-gas is chemically identical to natural gas. The e-gas will be used to power 1500 A3 g-trons, each of which will cover 15000km annually in trials. Audi is claiming a CO2 figure of lower than 30g/km even when the emissions for building the e-gas plant are accounted for.