Car culture derived from motor racing, modified car is to make a car more beautiful, but the car actually has a special function. There is a saying is the car with rear wing, can effectively reduce the car travelling at high speed when air resistance and fuel saving.
This claim was based on: during the vehicle running resistance can be divided into longitudinal, lateral and vertical rise of 3 aspects of the force. According to the test, when a car to 80 km / hour forward, 60% of the fuel is used to overcome the longitudinal resistance. In order to effectively reduce and overcome the air resistance when the vehicle high-speed impact, it is designed to use the car tail, and its role is to enable air to car produced fourth kinds of forces, namely the adhesion on the ground, it can partially offset by the lift, control car float, reduce the air resistance, the automobile can close the roads, in order to improve the running stability. Automobile tail shape and size is the result of accurate calculation of the designers determined, not too big nor too small, or it would increase the car driving resistance or not to play due role.
To exhaust volume of 1.8 liter sedan as an example, if mounted on the rear wing, aerodynamic drag coefficient decreases by 20%, the road, fuel consumption reduction may not obvious. If the highway at 120 km an hour driving, can saving 14%.
Dissidents think: drag coefficient : that the air resistance is a car encountered by the largest and most important external. Air resistance coefficient, also called the drag coefficient, calculation of automobile air resistance is an important factor. It is through wind tunnel experiment and gliding experiments as determined by a mathematical parameters, it can be used to calculate the vehicle on running air resistance. Appearance caused by resistance from the rear of a vehicle vacuum, vacuum region is wide, resistance of the greater. When the vehicle runs, had to overcome resistance mechanical loss resistance, rolling resistance of tire production ( also called the general road resistance) and the air resistance. As the vehicle speed increases, the air resistance is gradually become the main driving force, at 200km / h, air resistance is accounted for almost all the running resistance of the 85%.
The drag coefficient of the front wind resistance x 2 / ( x air density front front projection area of X speed square ).
But in fact adding tail does not reduce the vacuum zone size, so can reduce the drag coefficient, also cannot mpg!
There is a car that he and the tail up feeling fee oil, this is right. Because of the increased vacuum zone volume.
Although in the context of issues, there are different opinions and views, but one point can be determined, that is adding tail can improve the vehicle running at high speed stability, and fuel-efficient but is reduced in rear spoiler extra role.
