I have a TruXedo cover on mine. Maybe 2% increase. I just roll it to the front if I need to haul something tall. Keeps the bed dry and stuff out of sight.

 

I have a cover straight from MOPAR. Piece of crap lol. The anchors to hold the cover down are aluminum and have stretched out over time and wont allow me to keep my cover down very tight. I talked to the MOPAR parts dept and no luck, you have to buy a whole new cover for new hold downs. I believe it does help gas mileage, not a bunch but it does.

 

bad a$$ bike crescent!!

 

Tonneau save you 10% on highway driving.. so you make back the investment.
Or you could win a free one!

Bak Industries is giving away THREE Bakflip tonneau covers in the "I Need a Flippin' Bakflip" video contest.
Deadline May 17.
Enter to win here: http://wildfireapp.com/website/6/contests/104892

And join us on facebook at http://www.facebook.com/Bakflip

 

No way a tonneau will improve mileage 10%. Like was said earlier, MAYBE 2%.

 

I picked up 1mpg maybe 2 max. I live in AZ as well, and although it doesnt rain very often, the fact that I can lock the cover and it locks the tailgate in place pays for its self and then some. I haul a bunch of equipment worth a lot of $$$ that I want locked up nice and tight.

 

Tonneau cover will give you *******ly no increase in MPG's.

The box of your truck creates very little drag and is only (slightly) evident at speeds around highway speed

-edit-
What the hell is with the random censoring of words on this site? Why is virtua-lly censored?