Hi all I have been a lurker

on this site for about 6 months or better.
I used some of the mods on by 2001 Toyota Sienna and increased the MPG from an average of 18 to 22 by taking out all the back seats, spare tire, and removal of the roof rack.
Now I have traded it in on a 2007 Toyota Tundra SR5 Double cab with the 5.7 V8
Good news for my job, terrible news for my MPG.
The average according to the trucks computer when I bought it was 14.4 mpg
My average since I bought it is 16.2.
I decided to join the site and participate as I wish to increase the mpg of this truck to at least 22
I have read through many threads on modifications and am trying to put a list together in order of biggest bang for the buck.
Any suggestions are most welcome, keeping in mind that I still have to drive it for my job so I cant stick out like a sore thumb and I can not hurt the functionality.
I like the following ideas
- Front bumper skirt
- Operational Kamback Shell
- Side Mirrors replaced with cameras
The ones I have questions on are
Cold air Intake
Exhaust
Plexiglass over Recessed Fog lights
My questions are on price and return more then anything else