Based on the movement resistance forces, the vehicle longitudinal dynamics is related to power demand for a specific route. The vehicle gear shifting influences significantly the acceleration performance and fuel consumption because it changes the engine operation point and the powertrain inertia. This paper presents a study based on the US06 velocity profile that involves high speed and high acceleration phases, where the vehicle performance is limited by both the engine power and the tire traction limit. For improving the vehicle performance without increasing fuel consumption, a genetic algorithm (GA) technique is used Ver menos