A rail vehicle (10) with fuel consumers (20, 22, 30, 32, 34) and an on board fuel storage and supply system, characterized by a main fuel tank (24) adapted to be installed in a first railcar (12) of the rail vehicle (10), a buffer fuel tank (36) adapted to be installed in a second railcar (14) of the rail vehicle (10), and a fuelling device (38) for transferring fuel from the main fuel tank (24) to the buffer fuel tank (36).Preferred application to internal combustion engine rail vehicles with multiple railcars equipped with multiple diesel engines.