Frequent stops and starts for the traffic lights as well as acceleration/deceleration, rather than at constant speed, are the most common transient operating conditions. Consequently, understanding the dynamic characteristics of the powertrain system is vitally important in designing an efficient and fresh vehicle. To investigate the dynamic characteristics of the road vehicle performance, apart from a real road testing, it is necessary to set up a numerical test bed for dynamic performance simulation. The latter is even more convenient, costless and data repeatable. However, the aim of the present paper is to establish a computer simulation package by which the road vehicle power-train system design is developed for a small passenger vehicle based on fuel economy and performance. Furthermore, a proposed professional computer program of Automated Manual Transmission (AMT) system related to organizer algorithm of attractive gearshift requests is also introduced. The result of the proposed AMT ensures that the drive wheels force balance in order to keep gear shift, to kick down or up not only shift feel  but also the fuel consumption, and to alarm by near a specific failure or to get back system performance.