The ignition timing curve is different too, as at one point it goes flat.

My folks had a two motorhomes with propane ability. The first one wasn't all that great, but the second one (Promatic, I think) worked quite well.

Back then, the GM chassis had a lot of problems with vapor lock - this could easily be "cured" by running on propane until you got back into some cooler air. (GM's fix was to have you run a 1/2" steel line from the tank, along the outside of the frame, and then to the carb.) It also helped to wrap the lines in asbestos rope, and have plates that consisted of alternating layers of aluminium and asbestos gaskets, mounted between the carb and the intake.

The big advantage for my folks was, filling up in Mexico city for less than $10

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D