The enhancement of emission regulations and the enforcement of mileage regulations are a global phenomenon. To make engines satisfactorily meet such regulations in the short term, innovations in engine development technology are essential. In this paper, an innovative technique for the optimization of the transient performance of engines, ‘STATE’, was developed. Recently, the Design of Experiments (DoE) has gradually been used to optimize the static performance of engines, however it takes a long time to create a response surface model including all operating conditions of an engine. The newly developed technique ‘STATE’ shown in this paper was able to create the response surface model in a very short time by means of multivariate analysis of the transient performance data of time series. A new transient engine test cycle, named ‘universal mode’, was developed for the efficient creation of response surface models.