A car spoiler is a stylish automobile accessory that can be mounted on the rear of most cars. There are many different styles of spoilers. The general shape consists of a slender slightly downward angled piece of metal, fiberglass, silicone or carbon fiber that is usually the width of the vehicle. Some seem to appear to mold into the vehicle and others stick out with two small ledges on both sides.
The term "spoiler" is often mistakenly used interchangeably with "wing." An automotive wing is a device whose intended design is to generate downforce as air passes around it, not simply disrupt, or “spoil” unfavorable airflow patterns. As such, rather than decreasing drag, automotive wings actually increase drag. However, for the sake of this discussion, the rear wings on modern cars will be referred to as spoilers.
How a car spoiler works is simple. A spoiler is similar to an airplane wing, except where an airplane is using upward force, the spoiler uses downward force. By creating this force, the vehicle it is attached to is more capable of making sharp turns and maintaining traction on the road at low and high speeds. Normally, the weight of a car is the only thing that forces the tires down onto the pavement. Without spoilers, the only way to increase the grip would be to increase the weight, or to change the tire compound. The only problem with increasing the weight is that it doesn't help in turns, where you really want your car to grip. All that extra weight has inertia, which you have to overcome to turn, so increasing the weight doesn't help at all.
The advantages of this can be seen very readily. Instead of having a heavy car, which is slow, or having a very light car, which can slide away easily, you now have a car that sticks to the road better the faster it goes. Sounds perfect, right? There is one catch. Every time a spoiler generates down force it also generates drag. Drag is the natural reaction of the air to resist motion through the car. Drag is bad, because it slows down the car. So, more down force is good, but too much down force (i.e., excessive drag) is bad. Very high performance sports cars, like Le Mans or F1, have a ratio called the lift/drag ratio. The car designers try and maximize this so that the car has just enough force to get around the corners, but not so much that they are too slow. Indy cars, and ones that are designed like that can have down force up to 3Gs, at 200mph. That means they could hang completely upside down on the track, and as long as they kept going fast enough!
Spoilers first appeared in 1965 when the Chaparral 2C was fitted with an adjustable rear spoiler/wing. It was quickly imitated on such cars as the Lotus 49, Ferrari 250 GTO and the Shelby Daytona.
1965 Chaparrel 2C
Probably the most famous wing to appear on the roads arrived in 1969 with the Dodge Daytona (and later the Plymouth Super Bird, in 1970). A special aerodynamics package for the Charger featured a cone-shaped nose with pop-up headlights, and a 3-foot tall rear wing. This produced an extremely low .28g drag at 200 mph. Along with its unbeatable 426 Hemi engine, these cars dominated the NASCAR tracks.
1969 Dodge Daytona
The racing successes in the 1960s opened the floodgates to spoilers. Practically anything with performance appeal had to have a huge wing in the late 1970s to the 1980s, whether it was the boxy rear spoiler on the back of an IROC-Z, or the snow shovel bolted to the rear of the Ford Sierra Cosworth.
1986 Ford Sierra Cosworth
Rear spoilers in the late 60s/early 70s came in all shapes and sizes and were an integral design feature of these cars. Here are some photos of the fantastic variety that came out of Detroit during the “golden years” of muscle cars.
Mopar (Dodge & Plymouth)
1970 Challenger T/A
1970 Coronet Super Bee
1969 Mustang Mach 1
1970 Mercury Cyclone GT
General Motors (Pontiac, Oldsmobile, Chevrolet & Buick)
1969 GTO Judge
1970 Hurst Olds 442
1969 Camaro Z/28
1970 Buick GSX
American Motors (AMC)
This brings us to today. The modern Dodge Challenger has functional front and rear spoilers. When Dodge decided to build a production version of the 2006 concept car, it had to overcome a high speed stability problem that was inherent in the retro 1970 design. That shape was unsuited for the 176 mph top speed that was achievable with the new 425 hp. 6.1 liter Hemi. Jeff Gale, the lead designer of the Challenger exterior stated that countless hours were spent testing the new design in the wind tunnel to “find the right balance of lift and drag.” Eventually, a rear lip spoiler was designed based on the one on the 1970 Challenger T/A. This was also supplemented with a front air dam/splitter, adjustment to the angle of the front edge of the hood, and a few other minor tweaks. The result was a car that was totally stable at the car's top speed.
2008 Challenger SRT (rear spoiler)
2008 Challenger SRT (front spoiler)
2018 Challenger Widebody Hellcat