A turbocharged or supercharged internal combustion motive system for utilization of gaseous fuel stored as a liquid wherein the liquefied gaseous fuel is vaporized and warmed at least partially with heat removed from the compressed intake combustion air in the turbocharger or supercharger aftercooler. In a preferred embodiment, the compressed intake combustion air is first cooled in an aftercooler against an ambiently cooled coolant and is subsequently cooled in further aftercooler heat exchange passages against an intermediate coolant which transfers heat removed from the compressed intake combustion air to the liquefied gaseous fuel. Embodiments are disclosed wherein the saturated liquefied gaseous fuel is first subcooled and then pumped to pressures high enough for direct combustion chamber injection and another embodiment discloses vaporization of the saturated liquefied gaseous fuel with compression of the vaporized gas in a compression-type injection system or by low pressure carburetion into the internal combustion engine.