Determining a maximum dispensing efficiency of a dispensing point in a fuel dispenser and determining if a dispensing point has a blockage and/or a performance problem if the maximum dispensing efficiency is less than expected. The maximum dispensing efficiency is calculated by determining the dispensing events exhibiting the lowest time for dispensed volume from a set of volume and time pair measurements for the dispensing point. The dispensing events exhibiting the lowest time for dispensed volume that are used to determine the maximum dispensing efficiency are taken from dispensing events where the amount of dead time, the time between the activation of a fuel dispensing event and the engaging of a nozzle and the time between the disengaging of the nozzle and the deactivation of the dispensing event, and customer or pre-pay transaction controlled reduced flow rates are minimized. In this manner, volume and time data that include more than the minimum amount of dead time in a dispensing event are not used in the determination of the maximum dispensing efficiency.