Bi-fuel vehicles or otherwise known as
dual fuel are
vehicles with
multifuel engines capable of running on two fuels. On
internal combustion engines one
fuel is
gasoline or
diesel, and the other is an
alternate fuel such as
natural gas (CNG),
LPG, or
hydrogen. The two fuels are stored in separate tanks and the engine runs on one fuel at a time in some cases, in others both fuels are used in unison. Bi-fuel vehicles have the capability to switch back and forth from gasoline or diesel to the other fuel, manually or automatically.