They are designed to increase the down force on the windshield at higher speed thus creating MORE drag - probably works the wiper motor more too. From what I have seen it looks to me like the new Rain-X wiper blades are about the best thing going - really low profile - no "suspension bridge work" holding the blade - even pressure along the entire blade - just a bit expensive.
i've got valeo flatblades retrofitted to my car. looks nice especially since my wipers are right in the airflow.
they certainly look as if they would disturb less air than a standard wiper, but i doubt road testing could reveal any impovements. they have a small integrated spoiler on top, and as such they do wipe very well at higher speeds.
on the other hand they're less flexible, my left one does touch the outer curved corner of the windshield untill it moves up a little higher. might have to do with the fact the wipers still use the standard arms. i changed the angle.
they cost about 2 or 3 times as much as standard ones but imo they're woth is as they're still not showing any defects even when the change indicator that slowly colors yellow over time sugests they should have been changed long ago.
just remember your wipers sit in a high pressure pocket so they're not going to cause they much drag as it would seem.
I put some low profile "aero" blades on Marvin... can't say they really do much for F-E. They might have improved things an iota, because at highway speed, regular blades were jumping about at the base of the screen a bit, and trying to use them at any speed over 50 was a challenge, especially with a bit of headwind. These however stay on the screen and actually wipe at 60ish.
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
I built a small sheet metal windshield at the base of the hood to keep my wipers out of the airstream. Prior to this when driving through heavy fog, the fog would deposit streaks on the windshield glass that could be traced back to the slots in the wiper frame, from which I deduced that the airstream was passing through the wipers (and creating drag).
I screwed some soda bottles to the plastic vent cover and used a cigarette lighter to melt waves into it. This may make turbulence worse than the wipers,but I'm thinking it will break it up;making it less harmful. I don't know how much wipers can hurt FE anyway,but every little bit helps.
Rubber molding glued to the front and back of the hood. It was nice and flat to start with, but the compound curve of the hood edge caused it to buckle and get wavy (or was that where I had the clamps?) . I guess sheet metal, ala basjoos, or ABS, ala autospeed, would be best.