Gas internal combustion engine for vehicles, having: - at least one combustion chamber, which is designed to receive an air/gas fuel mixture for combustion of same therein, - an intake manifold, which is fluidically connected to the at least one combustion chamber and is designed to feed the air/gas fuel mixture to the at least one combustion chamber at specified times for combustion, and - an auxiliary starting system for starting the gas internal combustion engine, wherein the auxiliary starting system has: - an auxiliary fuel tank, which is designed to store an auxiliary fuel, - a control valve, which is designed to open or close a connection between the auxiliary fuel tank and the intake manifold, - an ambient temperature sensor, which is designed to produce a signal that indicates the ambient temperature of the gas internal combustion engine, - a crankshaft speed sensor, which is designed to produce a signal which indicates the crankshaft speed of a crankshaft of the gas internal combustion engine, and - a control unit, which is designed to receive the signal from the ambient temperature sensor and the signal from the crankshaft speed sensor and to control the control valve in order to open same, with the result that auxiliary fuel is fed from the auxiliary fuel tank into the intake manifold in order to start the gas internal combustion engine, if the ambient temperature is lower than a specified ambient temperature threshold, wherein the control unit is furthermore designed to control the control valve in order to open same until the crankshaft speed is higher than a specified crankshaft speed threshold. - at least one combustion chamber, which is designed to receive an air/gas fuel mixture for combustion of same therein, - an intake manifold, which is fluidically connected to the at least one combustion chamber and is designed to feed the air/gas fuel mixture to the at least one combustion chamber at specified times for combustion, and - an auxiliary starting system for starting the gas internal combustion engine, wherein the auxiliary starting system has: - an auxiliary fuel tank, which is designed to store an auxiliary fuel, - a control valve, which is designed to open or close a connection between the auxiliary fuel tank and the intake manifold, - an ambient temperature sensor, which is designed to produce a signal that indicates the ambient temperature of the gas internal combustion engine, - a crankshaft speed sensor, which is designed to produce a signal which indicates the crankshaft speed of a crankshaft of the gas internal combustion engine, and - a control unit, which is designed to receive the signal from the ambient temperature sensor and the signal from the crankshaft speed sensor and to control the control valve in order to open same, with the result that auxiliary fuel is fed from the auxiliary fuel tank into the intake manifold in order to start the gas internal combustion engine, if the ambient temperature is lower than a specified ambient temperature threshold, - an auxiliary fuel tank, which is designed to store an auxiliary fuel, - a control valve, which is designed to open or close a connection between the auxiliary fuel tank and the intake manifold, - an ambient temperature sensor, which is designed to produce a signal that indicates the ambient temperature of the gas internal combustion engine, - a crankshaft speed sensor, which is designed to produce a signal which indicates the crankshaft speed of a crankshaft of the gas internal combustion engine, and - a control unit, which is designed to receive the signal from the ambient temperature sensor and the signal from the crankshaft speed sensor and to control the control valve in order to open same, with the result that auxiliary fuel is fed from the auxiliary fuel tank into the intake manifold in order to start the gas internal combustion engine, if the ambient temperature is lower than a specified ambient temperature threshold,