Spoilers on a car are often considered to be the domain of sports or performance cars, although some production cars come with this accessory as a standard feature. What function does a spoiler on a car perform to make it a desirable feature?
A spoiler redirects the flow of air around the car. The spoiler “spoils” the normal flow of air and redirects it in an orientation that is beneficial to the performance of the vehicle on the road. This reduces drag and lift on the car, improving overall efficiency and road-holding at speed.
When a spoiler on a car is mentioned, most people think of the wing design on the car’s rear. A spoiler can be much more than this and can be installed in several locations on a car, but the spoiler’s purpose is the same, irrespective of its installed location.
What Is the Purpose Of A Spoiler On A Car?
The main function of a spoiler on a car has to do with the aerodynamics of the car and adjusts the flow of the air around the car as the car moves.
A spoiler redirects the natural flow of air around the car as the car moves. The spoiler channels the normal flow of air and redirects it strategically to the vehicles.
The two dynamics the spoiler acts on are the drag created by air friction and lift.
Drag is caused by wind resistance, usually caused by air flowing over the top of the car, while the lift is produced by air flowing under the car.
In the early 1960s, car manufacturers realized that airflow and aerodynamics affect a car in the same way as an aircraft. Designs changed to include aspects and features to improve the aerodynamics of cars to improve performance and fuel efficiency.
Adding a spoiler to a car came out of this understanding of the effect of airflow around the car as it drives. Spoilers have little to no effect on a car at slow speeds, but at high speeds, spoilers can make a significant difference to the performance of the vehicle.
As a result, most of the initial development around spoilers was in the motor racing industry in the quest for faster, more fuel-efficient cars with better road holding ability.
Spoilers contribute to all these aspects of high-speed driving, helping cars go faster on straights, corner faster, and use less fuel.
With the success of spoilers in the racing industry, they were incorporated into the design of street cars, in particular high-performance sports cars.
Where Are Spoilers Installed?
As we have mentioned, there are several locations on a car where spoilers can be installed to modify the airflow around the car and improve performance.
Spoilers can be installed at the rear of the car to provide downforce to counteract the lift and reduce air resistance over the car. The spoilers at the front of the vehicle called air dams, and sides of the car reduce the air flowing under the car, helping to reduce lift and drag.
The rear spoiler on the trunk of the car acts as an inverted aircraft wing, where the airflow actually helps to push the car down onto the road surface, increasing traction for the wheels on the road.
Spoilers at the front of the vehicle limit the airflow under the vehicle. The air sucked out from under the car at the rear creates a mini vacuum under the car at high speed. This vacuum serves to pull the car closer to the road surface.
The vacuum reduces the lift factor, thereby improving the road-holding of the vehicle, particularly when cornering at speed.
Spoiler Versus a Wing: What’s the Difference?
Many people use the terms spoiler and wing interchangeably when referring to the spoiler on the rear of the vehicle.
A wing is typically a large spoiler on a race car that provides additional downforce for the vehicle’s rear wheels. Spoilers are typically smaller, produce less downforce, but reduce air turbulence behind the vehicle, which improves the fuel efficiency of the vehicle.
Consequently, when people talk about a wing on a standard street car, they are generally referring to the spoiler on the rear of the car.
Can You Install An Aftermarket Spoiler?
Many people install aftermarket spoilers for several reasons, but this may not always result in the desired effects on your car’s performance.
Some people install aftermarket spoilers because they look cool, or they may think it will enhance the fuel efficiency, speed, and stability of their vehicles.
Unfortunately, with little understanding of aerodynamics, many people fit aftermarket spoilers incorrectly to their cars, with the resulting adverse effects on the car’s performance on the road.
Car manufacturers spend large amounts of money on building aerodynamic concepts into their designs. Installing spoilers can change the entire aerodynamic design of the car from the manufacturer’s original design resulting in a drop in fuel efficiency, top speed, and road holding of the car.
Some sports or performance model street cars come with spoilers as stock features on the car. These spoilers have been integrated into the design of the car and fit with the aerodynamic profile of the car.
As we have already mentioned, spoilers only have a real effect when the car is traveling at high speed, which means that the spoilers will not have any benefit to most street cars unless you are driving at highway speeds or racing your car.
This is why many sports cars have retractable spoilers that are folded into the car’s bodywork and only deploy when the car reaches certain speeds.
Consequently, most aftermarket spoiler fitments are for looks rather than performance enhancements.
Spoilers are designed to improve a car’s fuel economy, speed, and road-holding performance by adjusting the flow of air around the vehicle.
In most cases, car manufacturers incorporate aerodynamic research into the design of their cars. This means adding an aftermarket spoiler to a car can disrupt the aerodynamics built into the design of the car, producing undesirable results.
Cars that come stock with spoilers will function according to the manufacturer’s design, but aftermarket spoilers should be added to your car with caution.