Abstract: An additive dispensing system for diesel fueled applications includes a diesel fuel system having either single or multiple tanks, a fuel level sensor, an additive tank, a fixed rate additive dispensing pump and a microprocessor operating on a logic basis whereby a minimum of three fuel level readings, taken at fixed periods and compared to one another and/or to predetermined standards, provide the input necessary to control the operation of the additive dispensing pump so as to maintain a predetermined concentration of additive in the diesel fuel system regardless of random refueling sequences.