I remember those glass-clearing deflectors on the back of one of my parents' station wagons when I was a kid.
I would say those would make aerodynamics worse, not better. They increased projected frontal area, and as they blast air down the rear window, they would increase pressure drag aft of the deflector and increase the size of the trailing wake.
VG's could also increase projected area, but the theory (as I understand it) of placing them at the trailing edge of a vehicle is the tight vortices they create are supposed to extend the effective aerodynamic length of the vehicle: since the vortices would be drawn inwards in the low pressure area, they supposedly create a "virtual" boat tail, and minimize trailing wake.
I mounted mine along the trailing edge of the roof, without any on the sides. I still have a few extras that I have not installed. let me know how your A-B-A testing works out. I may install those later on.
Order some golf shoes, otherwise we might never make it out of this place alive.
I'm not sure of the size of these but they are supposed to be a certain distance apart or else the vortices don't form properly. Putting them too close together will make the adjacent vortexes interfere with each other.
The problem with the rear high wing is that it produces drag where as a vortex generator does not (not much anyway).
Ok the are 4" on centers and 3.25" wide so 3/8" between each so they are pretty close to each other. I would have thought they would be further apart to allow the vortex to be bigger.
There is / was a question 'way back when... "How many angels can dance on the head of a pin?" My standard answer : "Ball point or fountain?" LOL!
These tabs remind me of this scene.... But I DO appreciate the pic of the Gremlin! Wonderful! I couldn't get outta that ride soon enough! "Sicks" cylinder / automatic / power nothing / steering wheel like a Greyhound bus ... but it rode well with the large sway bars I put under it, front & rear...and the stiffer shocks I put in. Bench seats, no radio, just back & forth to work / stores. Deja Vu? In my "rear-vu" mirror I could see at last! No dirt, no rain beads! It worked for this! MPG gain? With a slip-n-slide automatic? Who even cared? I bought it off the lot (new) and I needed a ride, NoW!