Thanks for the replies to my enquiry about W.I. >From what I hear, I guess it is not going to be the solution to reduced fuel consumption on propane.Fortunately power loss is not a problem with a duel fuel system since full power can be regained by switching back to gasoline. One of the difficulties with stretching propane performance and consumption to it's limits is the need to compromise between the two fuels. Any significant alteration in timing or air flow will have a negative effect when running on gasoline. I am currently working on a simple vacuum operated air flow controller which will give provide optimum air/ fuel ratios for both fuels automatically. Best wishes, Tony V.