How does the rear-end spoiler work for car? Bernoulli effect or reducing turbulence? or what?

Question

I have browsed through some websites, but the explanations are not quite the same. Some explained that it reduces the turbulence. What does the turbulence do in the absence of rear-end spoiler? Or is it better explained by Bernoulli principle? Or both? Explanation with drawings (showing air flow or pressure) would be appreciated.

Answer 1

If you are going over 140 mph it puts a downforce on the rear wheels so they have more traction on curves.
Dragsters have them to add traction to the rear tires, but dragsters have Thousands of HP and are capable of slipping the tires up to 200 mph+
If they reduced drag, airplanes would have them, Some people think they make the car look like a high performance rig, so they caught on. Now everyone has to have a bigger one

Answer 2

The benefits of the rear spoiler is NOT to reduce turbulence, it's to add downforce to the rear of the car to provide better grip. The type of spoiler that can be used, along with the size, is usually determined by the governing body of the race (like NASCAR).

Answer 3

Back in the good ole days, the rear spoiler was first introduced on early muscle cars. these cars had tremendous amounts of torque and horse power. spoilers were used to keep more power and traction to the rear wheels at high speeds. so in affect, the air would push down on the rear of the car. remember the chrysler super bird using this at the daytona speedway? that was the largest of rear spoilers, and the beginning of more. like the pontiac gto. oldsmobile ralley 350,
all of the late 1960's and early 1970's. spoilers of today appeal to the eye of what people think looks good, rather than there real purpose.

Answer 4

Let me sort this out for you.

Rear-end spoilers on personal vehicles are for show. They were adopted from race cars as sporty expensive extras to sell the general public. If you notice, Indy and formula cars have spoilers in the front and rear to provide down force for lightweight race cars racing around flat surfaces. The down force gives them grip in the corners and they are able to maintain the higher speeds.

Notice also that you don't see much "drafting" in the corners in Indy and formula car races. Part of the reason is that when one car gets very close to the rear of another car, it takes all the down force off the car in the rear. In other words, the air is deflected over both cars, and the trailing car loses grip on the raceway surface.

The cars don't travel close enough together, the cars don't travel fast enough, nor are the highway curves sharp enough for spoilers to provide any value, except expensive aesthetic value.

Turbulence in the wake of passenger cars ain't a factor because the cars don't travel that close together.

Answer 5

It works like an upside down airplane wing..
The airflow causes lower pressure on the underside of
the spoiler which causes the spoiler to be pushed downward
which adds weight to the rear of your car as you go faster...

Answer 6

The only effective value to a wing on the rear is only practical above fifty mph to provide any usefulness so Oh yeah Look at me I B Kul

Answer 7

It's an unnecessary, fuel-wasting gadget which, as somebody correctly says, works like an upside-down aeroplane wing to push the car downwards to give more traction. Useful on a race track but nobody in their right mind drives fast enough on public roads to need one.