I just finished doing an e-fan on my tacoma I dont know if your truck has an electric fan but it made it so my "magic number" went up aka the number at which you get the best mpg but if i can go 57 instead of 53 that makes me happy I have a scangauge also and that helps! I am building a aero cap this summer which im told is far superior to a tonneau cover here is a link to a great build this guy is doing:
http://ecomodder.com/forum/showthrea...9-a-23152.html
hope this helps!!