This work is dedicated to study of time reduction for automatic transmission validation on emissions cycle. It has also summarized the main emissions regulations with their emissions cycles tests, like the US FTP-75 and European NEDC. Data acquisition was conducted through emissions cycles tests in a chassis dynamometer in four vehicles. Graphics were generated using the data collected showing driving time in each gear, the total amount of upshifts and downshifts, elapsed time in engine speed range and elapsed time in accelerator pedal range. Result showed that was not possible to eliminate validation tests completely, but it can be minimized and contributes to reduce timing in automatic transmission validation work due to running fewer tests.