How LPG AutoGas system works in a car.

Find out more about LPG autogas conversion.



STAG LPG/CNG systems for INDIRECT AND DIRECT injections engines


Netherlands PRINS systems


Italian BRC systems


VIALLE 5th Generation Liquid LPG Injection


There are 3 different types of Autogas systems and the different Autogas systems generally use the same type of filler, tanks, lines and fittings but use different components in the engine bay. Some injection systems use special tanks with circulation pumps and return lines similar to petrol fuel injection systems.



  • The Conventional Converter-and-Mixer System, commercialized in the 1940s and is still widely used today. This type of system uses a converter to change liquid fuel from the tank into vapour, then feeds that vapour to the mixer where it is mixed with the intake air.

The other two types are known as injection systems - a vapour phase injection system and a liquid phase injection system. There are differences between these two types of injection systems.


  • The Vapour Phase Injection Systems use a converter as described above for the converter-and-mixer system, but have a series of electrical shutoff solenoids and nozzles (called injectors) that are computer controlled and allows for accurate metering of fuel to the engine than is possible with mixers, improving economy and power while at the same time reducing emissions.
  • Liquid Phase Injection Systems do not use a converter, but instead deliver the liquid fuel into a fuel rail in much the same manner as a petrol injection system. Because the fuel vapourises in the intake, the air around it is cooled significantly. This increases the density of the intake air and can potentially lead to substantial increases in engine power output, to the extent that such systems are usually de-tuned to avoid damaging other parts of the engine. Liquid phase injection has the potential to achieve much better economy and power plus lower emission levels than are possible using mixers or vapour phase injectors.


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