I have noticed that you depend on your Sprinter van a lot, but with the rising cost of fuel I am sure you are feeling the pinch at the pump. I have been using LUCAS fuel treatment in my F-350 and I have gained 3-4 MPG. It works in both gasoline and diesel engines. I just wanted to let you know because as with all Americans feeling the strain at the pump, I am sure with eight kids anything that saves you money is a plus.