0
because that's what it is?
Liquefied Petroleum Gas = LPG
LPG: Liquefied Petroleum Gas
CNG: Compressed Natural Gas
lpg
liquefied petroleum gas
and
liquid propone gas
LPG stands for "Liquified Petroleum Gas" or "Liquid Propane Gas". The term is commonly used when describing the gas tanks of vehicles which run on such fuel.
methane