Do air tabs work?
 

Hi (New Post),

I'm Martin, a biz student/Entrepreneur located in Boston but originally from Toronto.

I've been looking into retrofitting cabs/buses/trucks with simple aero mods. In the past, I have started several successful unrelated businesses and am eager to try and commercialize aero mods. I've been looking at the Canadian company aeroserve technologies ltd. (the makers of the airtab) and am considering pursuing a business venture with them.

Can someone please enlighten me to whether these tabs would work on a coach bus or if these vortex generators actually achieve a 2-8% increase in MPG?

Cheers,
Martin

Good question ... a friend of mine has them all along the roof line of his Scion tC and swears by them ....

They didn't do squat on my Jeep cept keep the back window slightly cleaner on the hard top

got some links or pictures ? Anyone have access to a wind tunnel?

No.
http://autospeed.com/cms/A_3061/article.html

Ahhh I know what these are. I used these on my CO2 Cars!! (you always had an exit flat because of the minimum reqquirements for the Co2 cart hole dimensions this smoothed out the airflow by generating a vorte of air current. Shaved almost 2 tenths of a second off my Co2 cars run time! (same model ran 10 runs without then I added them and ran it 10 times again) I was impressed. I am not as certain how this would work scaled up. My models had wacky reynolds numbers that just do not scale up.

Might be worth trying though as they are very easy to make yourself. I do not think they would help that much on a car like mine but if you do have some sort of hatch it might work. If you are good at building them it might be worth a try IE it would not cost much at all so if it did not help you lost nothing except some time.

NOW in my case I was producing THRUST from the rear. The the vorticies had somewhere to go IE merge with. The thrust plume from the CO2 Cart. I would not think they would have a beneficial effect on a ballistic example such as our cars (its thrusting but via the ground so that does not count aerodynamically)

They might clean up airflow but they will not reduce drag UNLESS they eliminate an increase in drag from sloppy flow that is larger than there own drag contribution.

Huh at $2.50 I would not even bother making them myself and just buy them. Suck though no quantity discount. the 80 unit kit for truck/trailer is the same $2.50 per price.

you say no but the article states that there is a minor potential for increase... what gives?

I had them on my xA and they hurt my FE.

They work great, I think 2-8% FE Gains are way too conservative, I bet you get 40-60% FE Gains....In fact, I'll bet you could just put them on your car and they'll just push it down the road on their own...so just go ahead and rip the engine out of your car and let the aitabs just push you around town. You better have good brakes to keep your speed in check.

I'd say they're just oversized for use on a car.
Turbulator tape for gliders is (less than) 1mm thick, but AirTabs are 25mm or 1 inch thick as they were intended for use on big trucks !

VGs also add drag by themselves, so you need to overcome that first before you start gaining.

MetroMPG found they smoothed out the airflow on the back of a small sedan.
Red above found them to keep the rear window cleaner (indicating reduced turbulence at the rear).
They were found to improve stability when mounted underneath an Insight (1gen).

But so far, they weren't found to reduce the fuel consumption by EM members.