Drag is always kept to a minimum because it has a negative effect on performance as well as efficiency. The upright design of Indian buses gives it a drag coefficient of 1.30 while a raindrop has the least amount of drag.Now – a – days cars have a drag coefficient ranging between 0.4 and a low of 0.26. The power required in moving a body through the air goes up with the cube of the speed — so above 60 kph, a lot of power is needed to push a car to compensate the aerodynamic drag!
The reduction in drag in road vehicles can help in increasing the top speed of a vehicle and therebyits fuel efficiency, as well as many other performance characteristics, such as handling and acceleration. The two factors that have the main impact on drag are the vehicle’s frontal area and the drag coefficient.Firstly, the drag coefficient can be lowered which can be achieved by streamlining the exterior body of the vehicle. Streamlining the body requires characteristic use of the vehicle and assumptions over the surrounding airspeed. For high speed application especially at or above speed of sound, aSears-Haack body is used. This shape mainly consists of an elongated tube with pointed ends. For Deletion of aerodynamic drag Roof rack, Mud flaps, rear spoiler, Side mirrors, Radio antenna and Windshield wipers are used whereas for fabrication Wheel covers, Partial grille block, under tray, Fender skirts, modified front bumper and Boat – tails and Kammbacks are used.