Anyone have experience with propane injection for towing? Obviously I'm interested in a little more power, but also in mileage increases which these systems are supposed to give. Do they really increase your mileage? What do they do to your peak EGTs? For towing, they are supposed to use 1 gallon of propane for 4 gallons of diesel - is this your experience? What kind of system have you used, how big a tank and where did you locate it? Thanks!