Pennsylvania Statutes Title 71 P.S. State Government § 2201. Natural gas requirement

All vehicles purchased or owned by the Commonwealth after the effective date of this act may, whenever economically feasible, be converted to operate on natural gas as the primary fuel and have the capabilities of a dual fuel system. Any vehicle which has the capability of a dual fuel system shall have affixed to both front and rear bumpers a decal indicating the possibility of natural gas or gasoline in the fuel tank.