The study aimed to develop a method for assessing autotitrating CPAP efficiency. We tested devices from various manufacturers with different hours (h) of service. We used a polygraph to record flow and pressure generated by the autotitrating CPAP and a circuit closed by a valve as controlled leakage. The autotitrating systems were set in CPAP mode, and the measurements were conducted at various nominal pressure levels with and without an additional leak in the circuit. The system with most hours of service (6556 h) showed a difference between the nominal pressure and the measured pressure (>1 cmH2O) and an increase of the measured flow (+150%), with and without an additional leak. This difference was not evident in devices of the same manufacturer with less service hours (1443 h). In a device of other manufacturer with 1481 h of service, we found a difference at higher pressures, particularly with an additional leak in the circuit. In devices with few hours of service, the observed mild increase of pressure in the setting with an additional leak, is part of the correct behavior of compensation to ensure a correct pressure level in mask. This study provides a method for evaluating the efficiency of autotitrating systems using tools available in a sleep laboratory. The results suggest that there are differences in pressure and flow between devices from different manufacturers with varying hours of service. Further research is needed to determine the generalizability of these findings, but the study may have implications for clinical practice by highlighting the need for improved methods to evaluate autotitrating CPAP device efficiency.