When I was in HS (a long time ago) a school board member's truck, and a cheerleader, and his son spent the night in one of my dad's fields because he switched the truck from the full gasoline tank to the empty propane tank by mistake during some late-night tandem gymnastic maneuver. I was there, but was no help at all, since that was the night that I was introduced to Scotch whiskey and the aforementioned member's daughter.

Dual fuel has been around a while, and has gotten more than a few people in trouble over the years.

 

Aolt of cars in Dominican Republic run on propane, gas is expensive everywhere so alternatives are becoming popular