ISG(Idle Stop & Go) is a system for saving fuel during idle. The purpose of ISG system is fuel efficiency, Ecofriendly brand image and for meeting the federal regulations about emission. Especially ISG of auto-Transmission vehicle can save fuel consumption about 15% in traffic-jam mode. But system price is high to equip for small or diesel vehicle, so it is hard to be adopted many kind of vehicles. So the aim of this study is to introduce development stories of reducing system price. For these one, we made mule car and we can get feasibility test for development of system control logic.