To improve the fuel consumption of a motor grader, a method for shifting the power curve of the grader engine is proposed. The working principle, calculation method, and design procedure of the novel method are depicted. Considering the nonlinear and time-varying uncertainty of the load of a motor grader, the fuzzy adaptive control is provided to shift the power curve. The shifting action is decided by the gears and the corresponding engine speed together with the displacements of both the hydraulic pump and motor. As a result, the power line adapts to the frequent changes in different external loads. A prototype motor grader is developed to test the above-mentioned energy conservation method in different working conditions. The results show that the fuel consumption of the prototype motor is reduced by 23%-34% and the skip ratio is decreased by 10% compared with the traditional grader with only one power curve. The proposed shifting power curve method can be widely applied to other heavy-load construction machinery also.