A million years ago diesel was always cheaper that gasoline. I can remember when gas was twenty three cents a gallon that diesel was twelve. This would have been sometime in the late 50s.

This is why people bought diesel powered cars. And why big trucks were designed to run on diesel. Today big trucks used diesels because they last so long. Back in the thirties all engines wore out at about the same rate so the lower fuel cost tipped the scale to diesel.