Audi A3  Setting off  g-tron  Natural gas engine
Your vehicle will run on CNG (Compressed Natural Gas) and petrol. The fuel mode is changed over automatically.
Using compressed natural gas (CNG)
In addition to petrol, vehicles with a natural gas engine will run on either CNG, e-gas or biomethane.
The tank must NOT be filled with any other available types of fuel, such as LNG (Liquefied Natural Gas), LPG (Liquefied Petroleum Gas) WARNING! or hythane (a mixture of hydrogen and methane) Caution!.
Natural gas quality and fuel consumption
Natural gas is subdivided into two quality categories: Group H and Group L.
H-gas has a higher methane content and thus a higher calorific value than L-gas. The higher the calorific value of the natural gas, the lower the fuel consumption.
However, the methane content and the calorific value can vary within the same quality group. Consequently, the vehicle's fuel consumption can vary even if the gas tank is always filled with fuel of the same quality.
The quality of the natural gas is detected automatically. The engine management system adapts the vehicle set-up to variations in natural gas quality. It is therefore possible to mix both quality groups in the gas fuel tank. It is not necessary to run the gas tank dry before filling up with natural gas of a different quality group.
Safe operation of natural gas powered vehicles
If you notice a gas odour or suspect that the natural gas fuel system may be leaking, please follow the instructions below WARNING!.
  • Stop the vehicle immediately.
  • Extinguish any cigarettes immediately.
  • Switch off the ignition.
  • Open all the doors and the boot lid to ensure an adequate supply of fresh air.
  • Switch off or remove from the vehicle all items which could cause sparks or fire.
  • Do NOT drive on if the gas odour persists.
  • Obtain professional assistance. Have the fault rectified.
  • Serious personal injury can result if you ignore a gas odour inside the vehicle or when filling the tank.
  • Follow the instructions above Link if you notice a gas odour.
  • Leave the danger area.
  • If necessary, notify the rescue services.
  • Natural gas is highly explosive and highly inflammable. Improper use of natural gas can cause accidents, serious burns and other injuries.
  • The vehicle is not suitable for the use of liquefied natural gas (LNG) or liquefied petroleum gas (LPG) and must never be fuelled or driven with LNG or LPG. Liquefied gas can cause the natural gas tank to explode and can cause serious injuries.
The vehicle is not suitable for the use of hythane and must never be fuelled with hythane. Otherwise, serious damage to the engine and fuel system could result.
Have the natural gas fuel system checked at regular intervals by a qualified workshop.

All images, logos and text are property of © Audi. This site has no relationship with the company Volkswagen - Audi Spain nor any of its affiliates worldwide. For more information.