Anyone use those AirTabs to decrease drag?? - Page 2 - Fiberglass RV


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Old 08-20-2017, 03:49 PM   #15
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Name: K C
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They put then on the wings of airplanes....They create a small vortex which disrupts the airflow over the large surface area. By a little disruption of the airflow they help create create lift which without an understanding of aero dynamics seems illogical. But don't worry about how it works for airplanes, just realize what that device is doing is creating lift as well as disrupting the airstream.

You don't need to create lift on your trailer,not that it would make it actually fly up into the air or even do much in the way of lifting that heavy object as the trailer does not have the proper shape to function as a wing. For the best gas mileage you also want to keep the airflow smooth rather than being disrupted by a product specifically designed to create disruption.

People see things being done on airplanes without understanding why they are done and what effect they produce then copy it thinking it will help reduce mileage. This is one of those products where the maker got it all wrong. So forget about it, they are not going to save you gas money. You will be out the purchase price plus a little bit of fuel efficiency. It is indeed a scam put out by people to make a buck off of other people's lack of understanding of aerodyamics. Cheap to make...good profits..does not work as claimed because what it was designed to do makes absolutely no sense for use in a ground based vehicle.

Why would you put yet another item that causes disruption of airflow onto the surface of your trailer when we already have a lot of junk on the sides and top of the trailer that is already causing a disruption of airflow? We need less disruption of the airstream, not more, if you want to improve gas mileage.

As to sticking it on a window on the side of a trailer?
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Old 08-20-2017, 04:00 PM   #16
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Streamlining ?

I had put up some truck streamlining photos on line, it may have been on the old Yahoo Scamp site. The truck skirts, cab streamlining and flaps on the back of the trailer really do work, esp with trucks doing thousands of miles per week. And as I saw in Canada in July, and Nevada and Utah last week, often at over 75 mph. Certainly keeping your speed under 55 or 60 is the easiest solution. But I just returned from Bonneville Speed week a few days ago and saw many air control fins or blades or wings on cars going 200 to 250 mph, let alone the ones over 400 mph. ( Mickey Thompson and George Poteet ) And specifically, last year I saw the little vortex triangles on a big GMC fiberglas motorhome which was expected to go over 140 mph. ( It did not due to the poor condition of the salt ) These things work, but seem of little use to the casual fiberglas trailer owner.
But I still plan to experiment with some kind of small spoiler or wing on the fiberglas camper shell of my Ford Ranger. It already starts at cab height and gradually raises to almost the height of my Scamp 13'. Whether the possible changes will affect gas mileage enough to measure is uncertain but an interesting challenge. David Gearhart in Fresno and Sonora, CA (Photo (if it shows) is from 2016; a '53 Studebaker with air controls.)
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Old 08-20-2017, 04:15 PM   #17
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Quote:
Originally Posted by k corbin View Post
They put then on the wings of airplanes....They create a small vortex which disrupts the airflow over the large surface area. By a little disruption of the airflow they help create create lift which without an understanding of aero dynamics seems illogical. But don't worry about how it works for airplanes, just realize what that device is doing is creating lift as well as disrupting the airstream.

You don't need to create lift on your trailer,not that it would make it actually fly up into the air or even do much in the way of lifting that heavy object as the trailer does not have the proper shape to function as a wing. For the best gas mileage you also want to keep the airflow smooth rather than being disrupted by a product specifically designed to create disruption.

People see things being done on airplanes without understanding why they are done and what effect they produce then copy it thinking it will help reduce mileage. This is one of those products where the maker got it all wrong. So forget about it, they are not going to save you gas money. You will be out the purchase price plus a little bit of fuel efficiency. It is indeed a scam put out by people to make a buck off of other people's lack of understanding of aerodyamics. Cheap to make...good profits..does not work as claimed because what it was designed to do makes absolutely no sense for use in a ground based vehicle.

Why would you put yet another item that causes disruption of airflow onto the surface of your trailer when we already have a lot of junk on the sides and top of the trailer that is already causing a disruption of airflow? We need less disruption of the airstream, not more, if you want to improve gas mileage.

As to sticking it on a window on the side of a trailer?
So how does one reconcile this with dimples on golf balls?
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Old 08-20-2017, 04:25 PM   #18
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Name: David
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AirTabs ?

AirTabs might be helpful if placed on the back of the camper shell, rather than a wing, to lift the air over the trailer. ( I do get bugs on the front and top of my Scamp, so air is hitting it directly ) I may test that theory, especially since the AirTabs are only $2.75 each, and require only 3 per linear foot. The GMC motorhome I mentioned earlier had tons of AirTabs, but all were donated, so free. I did not get a chance to talk to that owner this year. (last week) David in Fresno, Sonora, Reno, Wendover, Ely . . .
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Old 08-20-2017, 04:30 PM   #19
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AirTabs might be helpful if placed on the back of the camper shell, rather than a wing, to lift the air over the trailer. ( I do get bugs on the front and top of my Scamp, so air is hitting it directly ) I may test that theory, especially since the AirTabs are only $2.75 each, and require only 3 per linear foot. The GMC motorhome I mentioned earlier had tons of AirTabs, but all were donated, so free. I did not get a chance to talk to that owner this year. (last week) David in Fresno, Sonora, Reno, Wendover, Ely . . .
Here is a photo, if it works, and is not upside down : The Motorhome is gutted and has a big roll cage.The biggest change is that it is dropped to the ground. David Gearhart , in Fresno today.
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Old 08-20-2017, 05:00 PM   #20
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I wonder if they work as well as magnets on the fuel line?

If you are interested in a small savings on fuel, just slow down a bit. The result is easily measured with your own mileage meter, without any sales reports, cost to purchase anything, installation work, comparisons to airplanes, or debates about wether it works or not.

Even if you do install them, you can still slow down and get measurable results, or are people buying them so they can drive faster with no additional fuel used?
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Old 08-21-2017, 10:03 AM   #21
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My wife wants to know if they will fit on the back of my belt. She thinks I need some sort of deflector.
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Old 08-21-2017, 10:50 AM   #22
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My wife wants to know if they will fit on the back of my belt. She thinks I need some sort of deflector.
Ha! Thare's an idea. Maybe it will make walking easier. Less turbulence around the mid-section. Maybe you're on to something.
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Old 08-21-2017, 11:23 AM   #23
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Originally Posted by Neto View Post
My wife wants to know if they will fit on the back of my belt. She thinks I need some sort of deflector.
Ha! Thare's an idea. Maybe it will make walking easier. Less turbulence around the mid-section. Maybe you're on to something.

Or could it be the train whistle and the gas that comes along with it that has her concern.
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Old 08-21-2017, 01:32 PM   #24
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Huh, and here I thought that - with how many 18-wheelers I have seen with those air-tabs on the top of their truck cab (plus the wing-type deflectors many truckers attach to the very back of the cargo compartment) - they must have SOME actual benefit, such as reduced drag.

However, from what the majority seem to be indicating, the only way to really reduce drag is to drive slower. Guess the old "Drive 55" is the key here.
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Old 08-21-2017, 01:43 PM   #25
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I don't think anyone is questioning whether large deflectors such as this, deflect air around a semi trailer.
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Old 08-21-2017, 01:46 PM   #26
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Some of those big wind deflectors I see sticking up on top of trucks look to me like they increase drag. Just a big barn door sticking up with a big vacuum and lots of turbulence behind it behind it.
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Old 08-21-2017, 01:47 PM   #27
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The difference between the large deflectors used by trucks, and these things, is large enough to drive a you know what through.

Do you think that major truck lines haven't tested big air deflectors on part of their fleets before adopting them?

http://s89686473.onlinehome.us/fit-airtabs6.jpg
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Old 08-21-2017, 02:09 PM   #28
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They look great

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