# Spoilers on cars - whufo? **URL:** \ **Category:** Factual Questions\ **Created:** [April 25, 2001, 10:04pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344 "2001-04-25T22:04:10Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sqweels](https://avatars.discourse-cdn.com/v4/letter/s/f19dbf/32.png) [@sqweels](https://boards.straightdope.com/u/sqweels)\ **Post date:** [April 25, 2001, 10:04pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/1 "2001-04-25T22:04:10Z")
I’m noticing more and more passenger cars with spoilers on the rear end. As I understand it, racing cars have spoilers to cancel or “spoil” the effects of aerodynamic lift at high speed and keep the wheels planted firmly on the roadway. But shirley, these effects are negligible on the freeway and the spoiler on your car is just there to look cool and even hurts performance with a little bit of extra drag. ---
**Author:** ![Gozu\_Tashoya](https://avatars.discourse-cdn.com/v4/letter/g/7993a0/32.png) [@Gozu\_Tashoya](https://boards.straightdope.com/u/Gozu_Tashoya)\ **Post date:** [April 25, 2001, 10:36pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/2 "2001-04-25T22:36:38Z")
Yes. FWIW, I once saw a van with racing stripes and a spoiler. The things people’ll do these days. ---
**Author:** ![Gunslinger](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)\ **Post date:** [April 25, 2001, 11:02pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/3 "2001-04-25T23:02:51Z")
> [@](#): > > \*Originally posted by sqweels \* > \*\*But shirley, these effects are negligible on the freeway and the spoiler on your car is just there to look cool and even hurts performance with a little bit of extra drag. \*\* Exactly. Unless you have a '69 Chaarger Daytona/'70 RoadRunner SuperBird\*, a factory-installed wing or spoiler (and most aftermarket ones) only hurts performance. \*–and those 2-foot-tall wings didn’t do anything until you hit 90 mph. 😃 ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 25, 2001, 11:35pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/4 "2001-04-25T23:35:33Z")
The Charger without the spoiler got kindof “floaty” at ~95-100 mph, so in that case at least it was a useful safety feature. ---
**Author:** ![donnie\_rotten](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@donnie\_rotten](https://boards.straightdope.com/u/donnie_rotten)\ **Post date:** [April 26, 2001, 12:25am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/5 "2001-04-26T00:25:10Z")
For the most part, deck spoilers are ridiculous, little pieces of plastic that “look cool,” but there are some passenger vehicles that have deck spoilers installed out of necessity, mostly German ones. The first year the Audi TT came out, for example, it “floated” so much that alarmed Audi engineers designed a deck spoiler to increase downforce at Autobahn speeds, which went into production the next year. The TT, if you aren’t familiar with this car, is a beautiful machine that due to its flat bottom and curved upper surface, is shaped in the general like an airplane wing. You could see that additional downforce would be a good thing on a car like this. Porsche has, on it’s newest 911 base model, an integrated “whale-tail” that sits flush with the deck at normal US highway speeds but extends at higher speeds to increase downforce. That idea first appeared, IIRC, on the Volkswagen Corrado, which had a deck spoiler that deployed at about 70 mph. So sometimes the things serve a useful function, but mostly they are there for show. Like, what is Pontiac thinking putting spoilers and ground effects on the SUNFIRE, ferpetessakes? ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [April 26, 2001, 1:30am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/6 "2001-04-26T01:30:26Z")
> [@](#): > > \*Originally posted by Gunslinger \* > \*\* > \*–and those 2-foot-tall wings didn’t do anything until you hit 90 mph. 😃 \*\* And what wankers those guys are. Oh, what I couldn’t do on a freeway pedestrian overbridge with twenty or thirty feet of stout rope and a large metal hook. 😃 ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [April 26, 2001, 1:35am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/7 "2001-04-26T01:35:10Z")
- - - For almost all production cars (like, maybe 98%), aerodynamic stuff is just for show. It doesn’t really do anything, except maybe hold up the center brake light. > [@](#): > > The first year the Audi TT came out, for example, it “floated” so much that alarmed Audi engineers designed a deck spoiler to increase downforce at Autobahn speeds, which went into production the next year. - Yes and no: flat underpanels are the best way to create downforce but to use them effectively, the bottom of the car has to be _sealed_, that is, _no vents_. Take a look at the bottom of any GTP car for an example. Nearly totally flat, with no vents at all. ~ Most production cars depend heavily on cooling airflow being forced in the front grille and downwards past the engine and trans and out though the bottom of the car. Blocking that airflow off results in the car’s quick and nasty death. - MC ---
**Author:** ![donnie\_rotten](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@donnie\_rotten](https://boards.straightdope.com/u/donnie_rotten)\ **Post date:** [April 26, 2001, 2:28am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/8 "2001-04-26T02:28:52Z")
My point was, in the TT’s case, the car floated too much, which neccesitated the addition of the deck spoiler. It’s not even that pretty a solution, just a little “lip” under the rear window… IIRC, the winged monstrosities referred to earlier, the Charger Daytona and Road Runner Superbird, were originally intended for NASCAR racing. They had the “dropped nose” and big wing for purely aerodynamic purposes. Ford attempted something similar with the Torino Talladega, which wasn’t winged, but had a somewhat aerodynamic front clip. To meet homolgamation rules then enforced in the NASCAR world, all these cars were produced in very limited numbers and sold to the general public. They are quite rare, and much valued by musclecar collectors (even though, IMHO, the Daytona and Superbird have got to be the UGLIEST rigs ever to take to a paced surface). But, back to the original OP: They’re purely cosmetic. Look at Pontiac. ---
**Author:** ![Spacegirl](https://avatars.discourse-cdn.com/v4/letter/s/e47774/32.png) [@Spacegirl](https://boards.straightdope.com/u/Spacegirl)\ **Post date:** [April 26, 2001, 2:48am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/9 "2001-04-26T02:48:10Z")
{{{{“Like, what is Pontiac thinking putting spoilers and ground effects on the SUNFIRE, ferpetessakes?”}}}}}} Hey, I resent that! I have a sunfire, and I like the spoiler. It doesn’t have to be a high performance car to have a spoiler, they just look cool. Most cars look better with spoilers anyway IMHO. Katrina (proud owner of a sunfire with a spoiler). ---
**Author:** ![Gunslinger](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)\ **Post date:** [April 26, 2001, 3:45am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/10 "2001-04-26T03:45:30Z")
> [@](#): > > \*Originally posted by donnie rotten \* > \*\*IIRC, the winged monstrosities referred to earlier, the Charger Daytona and Road Runner Superbird, were originally intended for NASCAR racing. They had the “dropped nose” and big wing for purely aerodynamic purposes. \*\* Yeah, I neglected to mention that while the wing didn’t do anything under 90mph, it raised the top speed to an oficially-clocked 201.1 mph lap (that includes the slowing down a tiny bit in the corners), and fans with stopwatches along the backstretch were reporting considerably higher speeds down the straightaway :eek:. > [@](#): > > \*\* Ford attempted something similar with the Torino Talladega, which wasn’t winged, but had a somewhat aerodynamic front clip. \*\* Actually, the Ford came first–the front of the Ford/Mercury wasn’t all that aerodynamic, just a semi-blocked-off grille\*. It was the long, sloping rear window (nearly horizontal when the front of the car was lowered) that got them up to 195 mph. Then the 'Bird and Daytona were built to lure Richard Petty back to MoPar. \*–unless you’re thinking of the Mercury Cyclone Spoiler II, which had a nose treatment very much like the 'Bird, but never raced (it debuted just as the aero cars were banned) ---
**Author:** ![Gunslinger](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)\ **Post date:** [April 26, 2001, 3:50am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/11 "2001-04-26T03:50:48Z")
> [@](#): > > \*Originally posted by TheLoadedDog \* > \*\* > > > [@](#): > > > > \*Originally posted by Gunslinger \* > > \*\* > > \*–and those 2-foot-tall wings didn’t do anything until you hit 90 mph. 😃 \*\* > > And what wankers those guys are. Oh, what I couldn’t do on a freeway pedestrian overbridge with twenty or thirty feet of stout rope and a large metal hook. > 😃 \*\* Nobody _drives_ an aero car; they’re too valuable. BTW, they had problems early on with the wings flying off in wrecks at speed…they ended up tied into the frame with steel cables. Now the Rice-boy winged Hondas, OTOH…I’ll carry the rope for you. 🙂 ---
**Author:** ![donnie\_rotten](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@donnie\_rotten](https://boards.straightdope.com/u/donnie_rotten)\ **Post date:** [April 26, 2001, 4:02am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/12 "2001-04-26T04:02:29Z")
Gunslinger, I stand corrected. I was thinking of the Cyclone. I’m humbled. As for those Hondas, I have a fairly stout Bungee cord here, will that do the trick? 😃 Oh, and BluMoon? My M3 is about as high-performance as a grocery-getting four-place coupe gets, and I don’t have a spoiler. 😛 Kidding… I kid cuz I love… ---
**Author:** ![Coldfire](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@Coldfire](https://boards.straightdope.com/u/Coldfire)\ **Post date:** [April 26, 2001, 11:04am UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/13 "2001-04-26T11:04:15Z")
> [@](#): > > \*Originally posted by donnie rotten \* > **The first year the Audi TT came out, for example, it “floated” so much that alarmed Audi engineers designed a deck spoiler to increase downforce at Autobahn speeds, which went into production the next year. The TT, if you aren’t familiar with this car, is a beautiful machine that due to its flat bottom and curved upper surface, is shaped in the general like an airplane wing. You could see that additional downforce would be a good thing on a car like this.** Which is why it isn’t a “beautiful machine”, but a major design fuck-up. Seriously: if a brand like Audi produces a “Sports car” (it isn’t, BTW. It drives like a friggin’ VW Golf), it had better take it seriously. Obvisously, they didn’t. The reason the Audi engineers were “alarmed” was that several first-year TT’s crashed at high speeds, leading to fatalities in one or two cases. Can you say “law suit”? It’s a boulevard cruiser for posers - not a sports car. But that’s all IMHO. 😉 Another car with a functional spoiler was the late 80’s [Lancia Thema 8.32](http://home.wxs.nl/~cate0025/). Sporting the 8-cylinder straight out of the Ferrari 308, it needed it, too! The spoiler would deploy at 80 km/h. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [April 26, 2001, 12:16pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/14 "2001-04-26T12:16:38Z")
> [@](#): > > \*Originally posted by KKBattousai \* > \*\*FWIW, I once saw a van with racing stripes and a spoiler. \*\* [http://www.eurekanet.com/~suprphreke/ateam/van.jpg](http://www.eurekanet.com/~suprphreke/ateam/van.jpg) (Una whistles the **A-Team** theme song to herself…) ---
**Author:** ![c\_goat](https://avatars.discourse-cdn.com/v4/letter/c/f4b2a3/32.png) [@c\_goat](https://boards.straightdope.com/u/c_goat)\ **Post date:** [April 26, 2001, 1:23pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/15 "2001-04-26T13:23:53Z")
A friend of mine got a 97 (I think) Toyota Supra. The spoiler on this thing is as high as the roof of the car (about 1 - 1 1/2 ft. high I’d guess). What’s the effect of a higher spoiler? Does it create more or less downforce? ---
**Author:** ![Coldfire](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@Coldfire](https://boards.straightdope.com/u/Coldfire)\ **Post date:** [April 26, 2001, 1:37pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/16 "2001-04-26T13:37:20Z")
More. The idea of a high spoiler is that it sticks out above the normal wind flow over the roof. Whether or not a Supra needs it is another thing. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [April 26, 2001, 1:40pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/17 "2001-04-26T13:40:30Z")
> [@](#): > > \*Originally posted by c\_goat \* > \*\*A friend of mine got a 97 (I think) Toyota Supra. The spoiler on this thing is as high as the roof of the car (about 1 - 1 1/2 ft. high I’d guess). What’s the effect of a higher spoiler? Does it create more or less downforce? \*\* One of the main problems with the low little spoilers (like the silly one on my 1998 Mustang GT, and all of the F-bodies) is that they are not in a section of the airflow that is undisturbed. Putting the spoiler higher places the spoiler in a section of the air flowing over the body of the car which is much less disturbed. The downforce generated is going to be primarily a function of the placement of the spoiler in the airflow, the geometry of the wing section, the angle of attack, and the size. It is interesting to note that I have seen top speed tests on my 1998 Mustang GT with and without spoiler, and noted that it seemed that removing the spoiler added about 3 mph to the top end. But there is of course a wide margin of error in measuring a small effect like that, and the tests were not scientific. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [April 26, 2001, 1:44pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/18 "2001-04-26T13:44:28Z")
Food for thought: Spoilers on most cars don’t produce much downforce, but don’t they reduce some turbulence aft the car and effectively reduce drag? ---
**Author:** ![Bawdysurfer](https://avatars.discourse-cdn.com/v4/letter/b/90db22/32.png) [@Bawdysurfer](https://boards.straightdope.com/u/Bawdysurfer)\ **Post date:** [April 26, 2001, 2:21pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/19 "2001-04-26T14:21:51Z")
“Spoiler” effectiveness is, as has been noted, a function of vehicle speed, and the level of engineering/design put into the effort. Some cars, primarily in various classes of racing, employ either an air foil, or flat, non-contoured plate. All things being equal,(which they seldom are) the foiled variety will net the greatest downforce with the least drag. One school says that the foil should be up above any of the turbulent air that is generated by the contours of the car. Wind tunnel testing, or a good analysis program will show a configuration that works with the flow characteristics of a given vehicle. This will let the foil be closer to a semi-laminar airflow nearer to the car. The structural considerations are then less significant for the given design. For Joe/sephine Blow, moderately high g forces at speed, in tighter than average turns, would be where a foil might most be noticeably functional. Several street cars have made compromising efforts at a speed based deployment wing. Porche was once one. “Effects Packages” are somewhat like tires. For the inexperienced, high performance rubber really only means that one is traveling at a noticeably higher rate, when the feces hits the airstream. The same could be said about ground effects. ---
**Author:** ![Hibbins](https://avatars.discourse-cdn.com/v4/letter/h/ce73a5/32.png) [@Hibbins](https://boards.straightdope.com/u/Hibbins)\ **Post date:** [April 26, 2001, 2:26pm UTC](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344/20 "2001-04-26T14:26:11Z")
Spoilers are put on a lot of vehicles as a visual cue that the vehicle is sporty. Often this is the only thing “sporty” about the vehicle. Personally I find spoilers a lot like tailfins on 50’s cars, more a styling point/fad than anything else. [Next page](https://boards.straightdope.com/t/spoilers-on-cars-whufo/63344.md?page=2)