There are two main LPG conversions delivery systems in use today, supplied by a number of manufacturers. they are known as the Mixer or single point, and the injector or multipoint.

For the early carburetor and EFI injection vehicles (pre 1992) where the engine does not use an exhaust Lambda Sensor and associated ECU we fit a Mixer system, that is installed into the inlet manifold just ahead of the air filter. This has the benefit of low cost and ease of installation. The downsides are that fuel economy, MPG can be approximately 25% down compared with Petrol and a slight hesitancy is felt when switching between Gas and Petrol. They had a big problem, the spit back, some times known as the BACKFIRE. this was a explosion that happened in the inlet manifold.

For vehicles (pre 1992 - 1997) where the engine does have an exhaust Lambda Sensor and associated ECU we can fit a Mixer system that is installed into the inlet manifold just ahead of the air filter, with a stepper motor controlled by the lambda sensor and a gas ECU (electronic control unit). This has the benefit of lower cost than the Sequential Vapour Injection (SVI) system again ease of installation. The downsides are that fuel economy MPG can be approximately 20% down compared with Petrol and a less hesitancy is felt when switching between Gas and Petrol. They also had the problem of the spit back / BACKFIRE when the car was running out of fuel or when it was running too lean for too long.

There was a system that came next to combat the spit back, this was known as DVI or direct vapour injection, the first of the multipoint systems, but this had a very short life 1999-2001 and was superseded by the Sequential Vapour Injection system.

For the modern vehicles (1997 - present day) they employ a Lambda Sensor or lambda sensors and an ECU. (electronic control unit) we install the latest Sequential Vapour Injection (SVI) system that places an individual injector above each cylinder resulting in maximum performance and economy. Typically fuel economy will be better than with the Mixer system and there is no hesitation when switching fuels. The downside is that the installation is far more complex and takes longer and thus is more expensive, but the chance of having a back fire has been eliminated.

Whichever system is installed you can rest assured that you will get a quality system that will reap significant savings for many years to come.