What is the purpose of the rear spoiler?

DougSlug · 03-30-2006, 10:23 PM

Does the rear spoiler (2006 MY) have a positive effect on the car's aerodynamics? Some mechanical engineer colleagues of mine insist that a spoiler would tend to increase drag by adding a downward force to the rear, but the effects would be negligible at normal speeds, which leads me to conclude that the spoiler is strictly for aesthetics. Was this just a design feature Toyota added to give the Prius a more sporty look?

- Doug

ghostofjk · 03-30-2006, 10:33 PM

This was debated a lot when the '01s first came out, and someone who was supposed to be a Toyota "insider" said that their wind tunnel tests showed it helped achieve the .27 drag coefficient a tiny bit. Don't know if that's true.

hdrygas · 03-30-2006, 10:42 PM

Well this may be more than you want to know but try this thread; http://priuschat.com/index.php?showtopic=17263 My answer is that it makes my backup camera dirty and well... me clean.

DocVijay · 03-30-2006, 11:00 PM

Spoilers do not always act to increase the downforce of the car. Spoilers also act to help the overal aerodynamics of the car. A spoiler disrupts the airflow and creates a bit of turbulence right behind the car. This actually is better with regards to aerodynamics. Another example is a golf ball. The dimples help to create turbulance behind the ball, which let;s it go farther. A smooth gof ball would not travel nearly as farr with all else being equal.

So for the Prius, the spoiler is not there to create more downforce at higher speeds. It is there to help the air flow around the car better, and it does the job quite well.

hdrygas · 03-30-2006, 11:21 PM

<div class='quotetop'>QUOTE(DocVijay @ Mar 30 2006, 08:00 PM) [snapback]232747[/snapback]</div>

Quote:

Spoilers do not always act to increase the downforce of the car. Spoilers also act to help the overal aerodynamics of the car. A spoiler disrupts the airflow and creates a bit of turbulence right behind the car. This actually is better with regards to aerodynamics. Another example is a golf ball. The dimples help to create turbulance behind the ball, which let;s it go farther. A smooth gof ball would not travel nearly as farr with all else being equal.

So for the Prius, the spoiler is not there to create more downforce at higher speeds. It is there to help the air flow around the car better, and it does the job quite well.
[/b]

Yeah that and make the back up camera lens dirty!

brasche · 03-31-2006, 04:12 PM

Looking forward to the day when car skins are dimpled like a golf balls.

darelldd · 03-31-2006, 04:33 PM

A spoiler should not increase down-force. That's the job of a tuned wing, as far as I understand it. A spoiler attempts to decrease the vacuum found behind any vehicle - by "spoiling" the otherwise more laminar flow of air over the rear end. Typically a spoiler should have sharp edges - unlike the one found on our cars. The one thing I can guarantee is that the "spoiler" on our cars is not there to provide down-force.

aaf709 · 03-31-2006, 06:08 PM

Actually in the Japanese Touring Package, the rear spoiler is even longer. If you saw last Wednesday's episode of South Park you would've seen it.

DocVijay · 03-31-2006, 09:02 PM

<div class='quotetop'>QUOTE(aaf709 @ Mar 31 2006, 06:08 PM) [snapback]233151[/snapback]</div>

Quote:

Actually in the Japanese Touring Package, the rear spoiler is even longer. If you saw last Wednesday's episode of South Park you would've seen it.
[/b]

I plan on getting that spolier from Sigma. I think it may help with the aerodynamics a bit more at highway speeds. ANyway, even if it doesn't, I think it looks nicer.

Betelgeuse · 03-31-2006, 09:12 PM

<div class='quotetop'>QUOTE(DocVijay @ Mar 31 2006, 09:02 PM) [snapback]233205[/snapback]</div>

Quote:

I plan on getting that spolier from Sigma. I think it may help with the aerodynamics a bit more at highway speeds. ANyway, even if it doesn't, I think it looks nicer.

[/b]

If you think it looks nicer, great. If you're actually expecting it will make a difference at highway speeds, I think you're going to be disappointed.

03-30-2006, 11:00 PM	#4
DocVijay Senior Member Join Date: Sep 2005 Location: Tampa, FL Posts: 1,455 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 1	Spoilers do not always act to increase the downforce of the car. Spoilers also act to help the overal aerodynamics of the car. A spoiler disrupts the airflow and creates a bit of turbulence right behind the car. This actually is better with regards to aerodynamics. Another example is a golf ball. The dimples help to create turbulance behind the ball, which let;s it go farther. A smooth gof ball would not travel nearly as farr with all else being equal. So for the Prius, the spoiler is not there to create more downforce at higher speeds. It is there to help the air flow around the car better, and it does the job quite well. __________________ -- Bjorn -- 2007 Dark Amethyst Lincoln Navigator L 2005 Magic Blue Volvo XC90 T6 AWD Coming in 2009: Chrome Orange Lotus Exige S * 2006 Classic Silver Metallic, Package 7+Leather * sacrificed itself to keep me safe Thanks Prius. My Prius Mod Website

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03-30-2006, 10:23 PM	#1
DougSlug Senior Member Join Date: Mar 2006 Location: Trenton, NJ Posts: 115 My Car: 2006 Prius Model: Package: #6 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Does the rear spoiler (2006 MY) have a positive effect on the car's aerodynamics? Some mechanical engineer colleagues of mine insist that a spoiler would tend to increase drag by adding a downward force to the rear, but the effects would be negligible at normal speeds, which leads me to conclude that the spoiler is strictly for aesthetics. Was this just a design feature Toyota added to give the Prius a more sporty look? - Doug

03-30-2006, 10:33 PM	#2
ghostofjk Unrepentant Nattering Nabob of Negativism (V.P. Spiro T. Agnew) Join Date: Mar 2006 Posts: 981 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	This was debated a lot when the '01s first came out, and someone who was supposed to be a Toyota "insider" said that their wind tunnel tests showed it helped achieve the .27 drag coefficient a tiny bit. Don't know if that's true.

03-30-2006, 10:42 PM	#3
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Well this may be more than you want to know but try this thread; http://priuschat.com/index.php?showtopic=17263 My answer is that it makes my backup camera dirty and well... me clean.

03-31-2006, 04:12 PM	#6
brasche Join Date: Jan 2006 Location: Orlando, FL Posts: 156 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Looking forward to the day when car skins are dimpled like a golf balls.

03-31-2006, 04:33 PM	#7
darelldd Prius is our Gas Guzzler Join Date: Jan 2006 Location: Northern CA Posts: 5,336 My Car: 2006 Prius Model: Package: #6 Thanks: 18 Thanked 44 Times in 32 Posts Friends: 12	A spoiler should not increase down-force. That's the job of a tuned wing, as far as I understand it. A spoiler attempts to decrease the vacuum found behind any vehicle - by "spoiling" the otherwise more laminar flow of air over the rear end. Typically a spoiler should have sharp edges - unlike the one found on our cars. The one thing I can guarantee is that the "spoiler" on our cars is not there to provide down-force.

03-31-2006, 06:08 PM	#8
aaf709 Ravenpaw of ThunderClan Join Date: Apr 2005 Location: San Diego, CA Posts: 3,839 My Car: 2005 Prius Model: Package: #6 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Actually in the Japanese Touring Package, the rear spoiler is even longer. If you saw last Wednesday's episode of South Park you would've seen it.