At this point I would love to break the 20mpg barrier. That would make me very happy. And yes, they do look much better than the plastic housing. I will more than likely make this purchase. Just looking for some possible statistics on air flow and fuel consumption after the installation.
I can tell you the recipe for 20 MPG in an 3.7L H3, but you won't like it.
Example: my 07 gets roughly 17.5 all around, it will do a 18+ on the highway if you stay at 75mph or below. Best it has ever done is 21 under perfect conditions at about 50 MPH on a 55 degree day with no wind, and that was only for about an hour drive. Worse in winter with winter fuel blend and cold temps, much worse if you add in head winds. My 3 has all the off road goodies, Rock Rails, UPC, Roc Doc Skidz and Diff Cover, BA Bumper, rides on 33" (305s) Mickey Thompson MTZs, has just OEM style roof rack cross bars, and the front is set at 23.4". Performance mods: Air Doc Intake, AFE Pro Dry-S filter, PCM tune, Efan conversion, and PP TB. So with that weight (close to 6000# with me in it) and those tires, 17-18 all over and better on occasions is pretty awesome.
To get 20MPG every day, you would need to keep weight down, so no winch bumper and probably not Rock Rails, keep the factory nose rake at no more than 22", nothing on the roof, run stock 32" street tires (open tread patterns and and wide tires knock MPG), add in my same mods, drive with a super soft foot and never exceed 70MPH. That would likely do it. With those performance mods and skinny 32" street tires, you would get some robust acceleration, but you would not be able to stomp on it and keep the MPG. Who wants to drive that hypothetical H3 and do it like grandma all the time?