Vehicle power performance is mainly affected by engine parameters, transmission ratio of main reducer, transmission gear number and transmission ratio, streamlined automobile, automobile quality, tire size and form, and driving conditions of automobile.
The influence of engine parameters includes the maximum power, the maximum torque and the shape of engine external characteristic curve.
(2) The influence of transmission ratio of main reducer. The choice of transmission ratio of main reducer mainly considers the use of automobile and the road conditions which are often used.
(3) The influence of transmission gear number. The number of gears in the transmission system is the number of gears in the forward gear of the transmission when there are no transmission and transmission. With the increase of transmission gears, the chance of engine working near maximum power increases, and the average power of engine increases.
(4) The influence of transmission ratio. The relationship between the minimum transmission ratio and the maximum transmission ratio of the transmission and the proportions of the transmission ratios of each gear.
_The influence of automobile streamline. The aerodynamic drag coefficient of a vehicle has an effect on its dynamic performance. Streamlinearity has a significant impact on the power and economy of high-speed vehicles, but it has little impact on the maximum road resistance that can be overcome by vehicles.
_The influence of automobile quality. As the total mass of the vehicle increases, the power factor will decrease, while the road resistance and acceleration resistance will increase. Therefore, for a vehicle with a certain rated load quality, on the premise of ensuring sufficient stiffness and strength, it is necessary to reduce its own mass as far as possible in order to improve the power performance of the vehicle.
_The influence of tire size and form. The driving force, rolling resistance and adhesion of automobiles are affected by the size and form of tyres. Therefore, it is important to choose the proper pattern and form of tyres for the power performance of automobiles.
_The main factors affecting the running conditions of automobiles are climate conditions, plateau mountainous areas, road conditions and so on. Vehicles traveling in Plateau area, because of the high altitude and thin air, reduce the inflatability of the engine and the end pressure of compression in the cylinder, resulting in the decrease of engine power. Under the condition of bad road and no road, the vehicle dynamic performance is greatly reduced due to the reduction of road adhesion coefficient and the increase of wheel rolling resistance.