i'll brook no dissent, but again... results not typical because *nobody* puts the time and effort into tuning their set ups-- or has the skill and understanding to do so.
at any rate, a well thought out and tuned 4bbl set up can and will absolutely return fantastic results. but most people either cheap out or only go half measures here.
and as you note, driving style (and terrain) play a huge factor in the grand scheme of things.
also, he's got a van with 3.55's and massive tires. so eeking out a few mpg might be a moot point. not saying it's impossible, but just less likely is all.