Back in '83-'84 my mom had an International 1010 Travelall. She had a place in Mexico she liked to spend time at. Mexican gas back then was bad (not sure if it's better today) and the truck ran very poorly on it (knocked & pinged). The answer was water injection. Turn the system on when using bad gas, turn it off when using good gas from the states. Not once did I hear her say it helped the mileage. It did act like an octane boost and let her run crappy gas....