A drive train arrangement includes an internal combustion engine with at least one cylinder having a combustion gas inlet, and an exhaust outlet; an exhaust gas pump having a pump inlet coupled to the exhaust outlet, and a pump outlet coupled to a vehicle air tank and to the combustion gas inlet. A first flow control arrangement controls fluid flow from the pump outlet to the combustion gas inlet, and to the vehicle air tank. Control circuitry controls operation of the first flow control arrangement. The control circuitry is configured to: acquire a first indication of an air pressure in the vehicle air tank; and control, in response to the air pressure in the vehicle air tank being below a first threshold, the first flow control arrangement to allow fluid flow from the pump outlet to the vehicle air tank.