Spoiler

What is Spoiler?
A device whose design function is to spoil unfavorable air movement across the body of a vehicle in motion.

Advantage of spoiler
It can improved vehicle stability by decreasing lift which may cause unpredictable handling of the car at high speed

Spoiler can benefit or worsen the handling of the car, this device is design to lessen the effect of drag by generating lift or generate down force as air passed the vehicle.

How spoiler works?
Generally work by distributing or diffusing the air flow passing over and around a moving vehicle, this distribution primary purpose is to reduce amount of lift or instability naturally generated by the body of the vehicle or also called aerodynamics. The airflow are varies to the body panels or by adding extra attachment to the body.

In cars increasing contact between the tire and the road surface will increase traction which it allows the vehicle in motion to brake, turn , and accelerate with more stability.

Basically drag increase the speed of vehicle but some spoiler are effective at very low speed often excessive drag at high speed, spoiler works at high speed often ineffective while moving at low speed.