Audi is adding a CNG variant to the new A3 family. The A3 Sportback 30 g-tron will go on sale in fall 2020 at a starting price of €30,706 in Germany, with launch in other European markets to follow at a later date. The g-tron can run on natural gas or biomethane.
It has 3 CNG tanks at the rear as shown in the infographic above, with a 9-litre petrol tank sandwiched between them. The one at the front of the petrol tank has a capacity of 4 litres while the two tanks at the rear can hold 7 litres each. Interestingly, the 4-litre tank is made of steel while the 7-litre tanks are made of fibre-composite materials, with each weighing 26 kg (57 lbs). The inner layer is a gas-tight polyamide vessel. The outer shell comprises two sub-layers: an inner layer of carbon fibre-reinforced polymer (CFRP) and an outer layer of glass fibre-reinforced polymer (GFRP) — for safety reasons. A cover likewise made of GFRP protects the tanks against stone impacts or other road influences.
Before the tanks are mounted in the car, they are pressure tested at 300 bar, far above the operating pressure of 200 bar. The vessels withstand a burst pressure of 580 bar, which is also well above the 470 bar required by law, Audi said.
The 1.5-litre TFSI motor develops 150 hp (110 kW) and 200 Nm (147 lb-ft) of torque, and is paired with a 7-speed S tronic gearbox that drives the front wheels. The CNG model is claimed to accelerate from 0 to 100 km/h (62 mph) in 9.7 seconds and on to its top speed of 211 km/h (131 mph), should such things interest you.
With full gas tanks (excluding petrol tank), the car claims an NEDC range of up to 495 km (307 mi) and a WLTP range of up to 445 km (277 mi).