A system includes a first diesel engine operable to drive a first device, a first DEF tank associated with the first engine and operable to provide DEF to the first diesel engine during operation, a second diesel engine operable to drive a second device, and a second DEF tank associated with the second engine and operable to provide DEF to the second diesel engine during operation. An external DEF tank is arranged to contain a quantity of DEF that is coupled to the first DEF tank and the second DEF tank and operable to selectively deliver DEF from the external DEF tank to each of the first DEF tank and the second DEF tank.