Hybrid Bumper Air Deflector?

I have a 2nd Gen with a Brute Force Fab hybrid bumper and I was wondering whether anyone makes an air deflector (ok, I'll call it a bra) that I could stretch over it when driving on the highway and then remove when I get to the mountains. My mileage has dropped about 4-5 mpg since I installed it, and I don't attribute all of that to the weight. I think the air going into the fender well is creating a lot of drag. Not much I can do about the flat front, but thought if I could get some material to stretch over the ends and add a couple of stays between the bumper ends and bottom, it would deflect the air around the wheels and fender wells. Before setting off on some time suck, I thought I'd ask around here.

Here's the truck in its frequent weekend environment (it's no longer my daily driver), and picking up a few mpg will make me feel like I'm doing something besides musing about the aerodynamics... second pic is of the fender well and mounting points I'm thinking about.

Thanks for any insight or recommendations.

 

Go get some HDPE sheets from your local home improvement store. You can cut it and shape it with a heat gun to deflect air around the tires. Then just make some mounting points on the frame and fenders that you can use wing nuts to hold it on with.

 

I've been looking at the bumper and how close it gets to the old mounting points, and I think I have my solution - my old bumper. It's a bit Beverly Hillbillies, but I think it will do the trick for getting better aero while I'm on the highway. Zip tie it to the bumper and when I get to the high country I can either throw the bumper in the back or stash it somewhere in the woods while we're on the forest roads getting where we need to go.