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Old 01-07-2021, 11:24 PM   #11 (permalink)
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Quote:
Originally Posted by Taylor95 View Post
The front ones I can definitely test. I still want to do that. I think coastdown testing would be the best method, but I do have a scangauge I could use too. The rear ones would require removing the tire no matter what... there is probably 1 cm in between the tire and the screws. Not to mention I also would need to remove some body paneling to put them back on.

That is good to know that dome cars come with gurney flaps from the factory. Mine hardly stick out at all so I would think that they are beneficial. It would just be a lot of effort to test...

It is worth mentioning that I did see a slight mpg increase my last fillup, which is the first one with my mods. It has been a lot colder lately, so I think I can attribute some of the difference to my mods. I will definitely get around to testing the front ones though, and postung what I find.
Gurney flaps are on wings. They're called tyre deflectors (tire deflectors in the US).

I will be very surprised if any on-road testing can repeatedly show the results of such a tiny mod on / off.

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Old 01-08-2021, 02:27 PM   #12 (permalink)
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Originally Posted by MeteorGray View Post
I'm too dumb to do pictures, but I can say they are not very large at all and certainly do not stick out from the side of the car. I doubt very much you would notice them if you weren't looking specifically for them. In fact, the first time I noticed my car had them was when I read some forum guy was looking for a replacement, since one of his had fallen off his Mazda3. They're only about the width of the tire, and they appear to be positioned to displace that tiny bit of air before it hits the tread.
I also have a terrible time posting photos. I’m not sure why that is so difficult to do on Ecomodder. Without a photo of yours Meteor, I believe we are talking about the same thing which many have called “spats” on this site.

From a different thread, I just learned that we may be using the term “spats” incorrectly going as far back as 2010. The correct term should be “tire “deflectors” so for myself I will drop the term “spats” going forward.

There is a component of lift as the front of the tire is exposed the oncoming air and is forced out to the sides. The mini air dam or “spat” in front of the tire should divert some of the air around the tire more smoothly. Some have suggested that car manufacturers may use them to cut down on noise as well.

I will try to find a link to a photo in another thread.
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The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.

Last edited by COcyclist; 01-12-2021 at 09:31 AM.. Reason: Clarification of terms
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Old 01-08-2021, 02:43 PM   #13 (permalink)
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I tried using the mountain sunset button. I can only see a square. Is this because I use Apple?

From this thread.

https://ecomodder.com/forum/showthre...ats-13669.html

FWIW, Julian has tested front tire spats on an early Prius (his version was more like “canoe boat tail spats” at page 6) and found increased lift, instability at speed and reduced mpg.
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The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.

Last edited by COcyclist; 01-08-2021 at 02:48 PM..
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Old 01-08-2021, 04:13 PM   #14 (permalink)
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I would assume that the use of front-of-tire-protuberances, whatever anyone chooses to call them, would have to be designed for and tested on specific vehicles, like other aerodynamic features need to be.

Anyway, I have faith that Mazda put them on my car for some good reason.

I can't prove that, however.

I know of at least one guy who replaced one that went missing on his car.

Faith is blind :-)
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Old 01-08-2021, 04:59 PM   #15 (permalink)
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Honda Clarity, rear wheels:


BMW 3-series, front wheels:


Mercedes S-class, front:


Toyota Prius, front:


GMC Sierra, rear:


Honda Accord, front:


Toyota Highlander, front:


Hyundai Sonata, rear:


Porsche Taycan, rear:


Porsche Taycan, front:


Chevrolet Suburban, front:
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Old 01-08-2021, 05:54 PM   #16 (permalink)
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But no Camry.

Quote:
Originally Posted by COcyclist
I tried using the mountain sunset button. I can only see a square. Is this because I use Apple?
No. But I don't know where you see the square. In the Preview Post window?

You can type [IMG]x[/IMG] or [img]x[[/img] where x is any valid URL and it should display.
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Old 01-08-2021, 06:41 PM   #17 (permalink)
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No. But I don't know where you see the square. In the Preview Post window?

You can type [IMG]x[/IMG] or [img]x[[/img] where x is any valid URL and it should display.
Permalink #13 just above the words “I tried”.

Thankfully, others have better skills and have posted some good examples done by car makers
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The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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Old 01-08-2021, 06:50 PM   #18 (permalink)
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Quote:
Originally Posted by MeteorGray View Post
I would assume that the use of front-of-tire-protuberances, whatever anyone chooses to call them, would have to be designed for and tested on specific vehicles, like other aerodynamic features need to be.

Anyway, I have faith that Mazda put them on my car for some good reason.

I can't prove that, however.

I know of at least one guy who replaced one that went missing on his car.

Faith is blind :-)
There is plenty of evidence that front wheel deflectors reduce drag. But only by a small amount - eg 1 per cent. As I say, I doubt if it would be measurable by any on-road test.
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Old 01-08-2021, 08:27 PM   #19 (permalink)
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But no Camry.
Not of that generation, no. I wasn't interested in the undersides of cars back then!
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Old 01-08-2021, 08:54 PM   #20 (permalink)
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http://not-a-valid-URL.html

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