A rear spoiler affects the flow of air over a car to improve aerodynamics and reduce drag that can slow a car down. A rear spoiler is common in sports cars and can signify a car's performance level. On the other hand, many spoilers are added to passenger vehicles purely for decoration and serve no other purpose.

Purpose

A rear spoilers disrupts, or "spoils," the flow of air passing over and around a moving car. The faster a vehicle moves, the more wind resistance the vehicle experiences. By reducing the wind drag, spoilers increase fuel efficiency. They also allow for less of the engine's power to be used while the car is running.

Operation

The air relative to a moving vehicle is called the laminar flow. The laminar flow is disrupted by the car itself, creating a turbulent flow. A car must work harder to pass through turbulent flow, and thus it burns more fuel. Rear spoilers transform turbulent flow into laminar flow by changing the angle at which air flows off the roof.

Construction

A rear spoiler can be made from a variety of materials, but most are made of a lightweight type of plastic called acrylonitrile butadiene styrene. Fiberglass and metal are other possible materials, although they are more expensive. A spoiler is often painted to match the color of the car.

Decorative Spoilers

Auto manufacturers have started including rear spoilers on passenger vehicles for purely cosmetic reasons. Because they were most frequently used on sports cars in the past, rear spoilers on nonsports cars give a sense of power and excitement to a practical vehicle.

Wings

Spoilers are often confused with wings. Wings look similar to a spoiler but are used to counteract the lift that can occur when a car moves at very fast speeds. Wings are mounted much higher than spoilers and are typically used for racing vehicles.

Source:

Physlink

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