I have a 1970 Dodge Power Wagon 3/4 Ton 4x4. It has a late 1970's 318, and it is a 4 speed transmission. I was thinking of using it in the winter, but the fuel milage scares me. My Challenger gets about 8 mpg, and I cant afford something like that during the winter. Does anyone have a rough Idea of a Stock 318/4 speed MPG.