More than 65% of electricity consumed worldwide by the industrial sector is used in electric-motor-driven systems. For this reason, the efficiency of electric motors is an important factor in improving the energy efficiency of the industry. Additionally, this contributes to reducing energy consumption, production costs, as well as CO2eq emissions. The replacement of motors with efficiency class IE1 by motors of efficiency class IE3 is one possible alternative to increase the efficiency of electric motor systems. When a program to replace motors with others of greater efficiency is initiated, it is necessary to casuistically evaluate all identified opportunities. Economic viability can be evaluated using a variety of methods. Often, the methods recommended by manufacturers or consulting entities focus on simple payback time without accounting for all influencing factors. This paper contributes to the academic discussion by proposing a methodology based on the calculation of energy-saving potential, by performing a preliminary an a priori evaluation and determining the economic opportunities. It avoids evaluating all motors in the studied facility and shows its effectiveness by using the cost of energy saved to distinguish which motors to evaluate. Finally, it provides a complete economic evaluation of the final decision on the basis of discounted cash flow methods. A short-production-cycle sugarcane industry was used in the case study.