A method and apparatus for monitoring and determining fuel vapor recovery performance. The dispensing of liquid fuel into a tank by a gas pump nozzle displaces a mixture of air and fuel ullage vapor in the tank. These displaced vapors may be recovered at the dispensing point nozzle by a vapor recovery system. A properly functioning vapor recovery system recovers approximately one unit volume of vapor for every unit volume of dispensed liquid fuel. The ratio of recovered vapor to dispensed fuel is termed the A/L ratio, which should ideally be approximately equal to one (1). The A/L ratio, and thus the proper functioning of the vapor recovery system, may be determined by measuring liquid fuel flow and return vapor flow using a vapor flow sensor on a nozzle-by-nozzle basis. The determination of A/L ratios for individual nozzles are calculated using a reduced number of vapor flow sensors.