This paper deals with the estimation of power consumption for an unmanned road vehicle, according to the degree of steerability, the degree of redundancy and the path curvature changes. Thus, the main dynamic behaviors inducing directly or indirectly the power consumption for an autonomous road vehicle are considered for uniform and uniformly variable motions less than 15km/h. A comparison between different scenarios of piloting has been validated experimentally and through co-simulation using professional real-time dynamic vehicle simulator namely SCANeR Studio(c).