What is the deal with the new small overhangs that they are putting on boxier vehicle’s top backend? It looks terrible, but I am guessing it somehow shapes airflow and therefor helps fuel efficiency? It is way to ugly to be stylistic.
I first noticed it on Toyotas, so I call it the “Toyota Tail.” I have noticed it on some other vehicles also.
Please fight my ignorance on this, but aren’t spoilers mostly useful at high speed by keeping the back wheels on the gound? That doesn’t seem so applicable for front wheel drive vehicles and non-sports cars.
That leaves an aesthetic portion. Maybe some people think it looks good?
Did you read the article?
“Spoilers for cars are often incorrectly confused with, or the term used interchangeably with, wings. Automotive wings are devices whose intended design is to generate downforce as air passes around them, not simply disrupt existing airflow patterns.”
Sorry about that, I confused spoilers and wings. Ignorance fought.
But the wiki article also mentions that “Often spoilers are added solely for appearance with no thought towards practical purpose.”
This is what I am really trying to get at. Are these things showing up on cars because they are actually good for something or is it just another fad? Spoilers have been around for a long time and I have never seen them on large slow SUVs before, so they can’t be that useful.
My impression, and it may be totally wrong but it seemed like a practical application, was that the ones you see on SUVs are designed so as to reduce the amount of dust that collects on the large rear window of your typical vehicle. This would be increasingly important if you have that window open as you’re driving, especially off-road. Maybe it also helps to reduce the amount of water rivuleting across the surface and distorting the view during a rainstorm.
I’m fairly sure the “keeping crap off the back” is the main reason why they’re on SUV’s and other boxy cars. On snowy roads, the dirty water kicked up off the road rapidly gets sucked into the vortex behind a flat-backed car, soon rendering the back of the car completely opaque. The spoilers actually do make a big difference in breaking up that back vortex and keeping crap off the back of the car.
I don’t think it’s for looks, no one looks there on a SUV anyway. If it weren’t there, you’d basically have a square and a lot of turbulent air swirling around the window. Adding a spoiler certainly smooths that out. It may help keep the window clean but I’ve never noticed. In my experience, the area under the spoiler is usually pretty gunky and water runs off of it onto the window, leaving streaks and depositing even more gunk. Of course, vehicles and spoiler designs vary.
Dirt, rain, snow, etc. accumulating on the rear window may all be caused by these unfavourable air movements.
Other factors may be wind noise, rear wiper problems, or even exhaust direction.
I’m with this explanation. When we got our first minivan (in the 80s, when they were first hitting the market), the back window would get completely occluded with dust in just a few days. My father installed a rather ugly aftermarket spoiler or wing or whatever you want to call it over the window, and it cut down on the dust dramatically.
My father told about a panel truck he bought, with no back door. No one would ride with him and he had headaches until he got rid of it. ('30s) No spoiler! They thought there was something wrong with carburetor or something.
Roofline spoilers are nothing new on big vehicles. My family used to have a 1973 AMC Ambassador station wagon, and this monster had a spoiler (covered with wood-grain vinyl!) at the top of the back window.
Much like svd678’s father’s truck with no back door, it was common to drive station wagons with the back glass down, so anything to shape airflow and keep the engine’s exhaust from coming in to gas the kids in the rear-facing seat is probably beneficial.
Lacking the spoiler in question, airflow over the top of the vehicle will swirl back when the roofline ends and swirl against the rear window (back of vehicle). This turbulence is friction and maybe even have a slight sucking effect.
If you extend the roofline via a spoiler the air will swirl down but a pressure bubble, for lack of better words, prevents the turbulence from buffeting against the rear window (back of vehicle).
In NASCAR, you see this effect when someone rides up to the rear of the bumper in front of them. Without the cars touching, the lead vehicle gets an aerodynamic boost, because the airflow that would drag against the rear of the lead car is diverted over the car that is right up behind the lead vehicle.
That spoiler trailing off the back of SUVs/Vans is to reduce drag and lend one more little bit of help towards fuel economy.