Who the hell are you? You show up here and with your second post call me a liar? Or at teh very least call me an idiot? I know enough to check controlled factors versus variables. I lived in florida, flatland, summer temps, (consistently 90+ degrees on dry albeit humid days). Three trips same routes, same vehicle weights as I was by myself. (including fuel amounts)
All that aside, I know how to divide my mileage by my fuel capacity which at the least says I lost 5 mpg due to my a/c unit. There is no variable you can offer that can account for a 5mpg loss. Any variable you have, wind speed, tire pressure, etc. at the most will account for 1/2-1.5 mpg.
There are times when I am wrong with a post, and there are times when I have called someone wrong. However it was situations that are provable or have already been verified by reliable sources. I DONT tell anyone "they are wrong" unless I can prove it. Especially with fuel mileage, you shouldn't either.
AllanD, Wicked, and a few other have a reputation around here that they can say what they want and I will eat it up. You however have two posts and nothing to prove you know anything about my vehicle or what you are talking about.
That said, welcome to the site, I truly hope you enjoy it and don't let my mild berating discourage you. You will enjoy it here.

Have one on me.