VW Vanagon dual fuel conversion. 
Van operates on propane or gasoline.  Fuel choice is selected by an electrical switch on the dash.  You can switch fuels "on the fly". Solenoid valves control the flow of propane and shut off the fuel injectors.  The digifant ECU looks after ignition for both fuels.  Range of the van is extended by 300 kms.  I live in Canada and operate the van on propane 99% of the time.  Automotive propane is widely available here and is subject to less tax than gas or diesel.  The van runs smoother and quieter and the idle is smoother than with digifant.  With careful tuning and proper design and installation you do not notice any power difference between propane or gasoline.  No internal engine modifications are necessary.  EGT and water temp remain the same as with gasoline.  Starting in cold weather is easier than with gasoline because the fuel is in a gaseous state as it enters the intake tract, it does not condense.  Cold start enrichment is not needed.  Propane requires a higher voltage across the spark gap than gasoline,  your plug wires and coil have to be in good shape.  I've never had a problem using stock VW ignition systems with propane, I've converted both the WBX and inline 4 and have not had any problems.
This page is posted for information only, I do not have any propane systems for sale. 

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