In a strict sense of MPG, can a CAI like the S&B dry filter setup be justified?
If I can sneak another 1-2mpg out of the truck that would put me over 20 and I would be a happy camper to say the least.
I hate the stock air boxes on just about any rig.
However the dry filters like the Donaldson filter don't flow bad and are proven to filter better under most circumstances
Have you modded the stock air box yet, for better flow ?
I'd give that effort a go before I pointed you toward spending money on a fancy air box, see if it helps. But if you're anything like me, you'll wind up with an aftermarket piece soon. If you do choose to go aftermarket find a set up that offers a bumper scoop or "ram air" scoop and a box that's completely sealed from the engine bays hot air
That's my .02