Nowadays, the eco-driving technique represent one possible mean to reduce the energy consumption and the pollutants emission of vehicles. Besides the very low investment needed for such an option, its suitability to be applied even to old vehicles makes its impact important and immediate. The work presented here aims to quantify in a first approach the potential gain allowable by an eco-driving behavior for a given vehicle using numerical optimization methods (only the case of conventional ICE based vehicle is detailed in this paper). Then, an Advanced Driving Assist System (ADAS) based on the proposed optimization has been designed and tested. The design approach takes into account the different constraints that could appear like the traffic limitation, the safety, the pollution but also those related to the driver receptivity and his ability to understand and apply the information given.