Air Tabs

[skyking]

note that they are placed upstream of the (too steep) back glass, presumably to improve attachment there. It could show up in that case.
Where we used them was leading edges of airplanes, to preserve attached flow at a higher angle of attack. This was at little to no drag penalty. It was done after a great deal of research.
To simply stick some on like the back of that 'vette above, and make some claim is ludicrous.

[slowmover]

The single consistent report I see or hear from other truck drivers is that mirrors stay cleaner, and the "wake" at the truck rear is easier to see through (dust, rain, etc). The rear doors of a van remain clean-er. That'd be enough for me to try them were I a big truck/trailer owner.

[wyatt]

Originally Posted by slowmover

The single consistent report I see or hear from other truck drivers is that mirrors stay cleaner, and the "wake" at the truck rear is easier to see through (dust, rain, etc). The rear doors of a van remain clean-er. That'd be enough for me to try them were I a big truck/trailer owner.

Mirrors stay cleaner? Where are they putting these things? When we put them on the van, they only altered flow from where we put them on back. I could believe that the wake would be easier to see through (presumably faster moving, pulling the wake inward thus easier to see around the rear wake), I am sure it would have helped keep my friend's rear window stay cleaner, but I don't understand how it would possibly help keep mirrors cleaner (unless maybe it's a mirror that helps to keep an eye on the rear door of a cargo vehicle...). At any rate, my friend was going for low drag, so when our little test showed that his van had higher drag with than without, they didn't get any more investigation.

[luv2spd]

I put some on my '98 Accord, even if they don't work I think they look cool.

[luv2spd]

[luv2spd]

What I mean by "don't work" is that they do not improve fuel consumption; running in the rain you can clearly see that there is no flow separation below 110 km/h. The air tabs were $50 plus $100 to paint them.

[RiderofBikes]

for these to have little to any affect, wouldnt these tabs be best placed while still in direct and attached flow of the air on top of the car, to help attach the air flow further past its point? like say, not the end of the roof, but more midway, at the apex of most vehicles roof line, when its just starting to curve down to match the rear window. Of course this might add to the Cd of the vehicle but may give something more conclusive?

[euromodder]

Originally Posted by RiderofBikes

for these to have little to any affect, wouldnt these tabs be best placed while still in direct and attached flow of the air on top of the car, to help attach the air flow further past its point? like say, not the end of the roof, but more midway, at the apex of most vehicles roof line, when its just starting to curve down to match the rear window.

Though they seem to be a bit too far aft in luv2spd's pics, the airflow over a car's roof is still OK beyond the apex, as the curvature is smooth.

[jakobnev]

luv2spd -
Now that you have those things on the roof you might look into having a sharper separation edge/lengthening/spoiler for the rear hatch.

[luv2spd]

The brochure says "Airtabs are also effective on roof trailing edges of automobiles with a rear window slope exceeding 30 degrees."