ELI5: Explain Like I'm 5

Bi-fuel vehicle

A bi-fuel vehicle is a type of car that can run on two different types of fuel - usually one of them is gasoline and the other is either diesel or natural gas. It's like having two cars in one! This can be useful if you don't have access to one type of fuel but you do have access to the other. It can also be more economical because you can use the less expensive fuel when it's available.