Attached is what our rig looks like now. I've noticed a drop in my MPG since last year, I've only owned it for 18 months or so but I have 4000 miles or so on it over that time.I'm wondering if others with similar setups have noticed anything or am I silly for hoping for better mpg. Last summer I was seeing 6, 7 or even 8 mpg one time. Now I saw 6.3 once and the rest has been 5.5 or so, lots of hills and starts and stops though. This last trip was 5.66 mpg over 583 miles and we moved everyday, so lots of airing up time every day. I try to cruise around 63-65 on the interstates, and posted anywhere else. I run my tires pretty firm, 100-110 all around.What has changed since then?Added roof rack and solar - added air resistance, thinking of adding air dams or some sort of skirting to clean up the air flow.Built out more / added significant weight, not sure how much quite yet.Adjusted throttle linkage to get more pedal travel - this could be it here as well. I still don't hit WOT even now, but before I'd say at best I got 65-70%, now I'm at 80% or so I'd say. I could just be accelerating too fast, but I feel like I'm just turtling along most times.Did have that over heat in the black hills, but this trend has been going on since before that.I'm calculating my mpg by entering in the milage from my hub odometer into a spreadsheet, but I'm starting to also question if that is accurate. I also have a GPS with trip odometers, I think I should cross reference the two to verify my data.Any other ideas? Is this just the way she goes?