I've been keeping track of my MPG for years and years...I mean like 20+ years....don't know why, just keep doing it...put me in the neurotic category I guess...I don't do it to change my driving habits to max MPG, or anything like that...I just keep recording it cuz I'm curious.
I got 21 or 22 twice, all stock, all highway driving (actually it was driving to Moab 2009 and then driving to New Mexico to meet up with some other Moab-bound VXer, and then drive up to Moab.
Seriously, I do remember there was a tremendous (I mean MEAN) tail wind on the NM trip...it just HAD to have an affect, cuz I had skids, roof rack, f/s spare in basket...and of course I did factor in the adjustment for my larger tires.
So I know it's "possible" but extremely unlikely to hit the 20s for anything but a stocker w/o sticky rubber. I also believe the summer/winter gas formulation has a tremendous impact on it (in places where that exists).When I lived in LA the winter gas (pretty sure it was the winter formula) dropped my MPG by at least 10%...booo!!! So maybe some of that issue is affecting MPG on some VXers?
Some here mentioned they had some increase in MPG when they used Premium all the time.....so I tried that for a while...like 13 months!....didn't see much difference and went back to regular.