I don't think this is bullshit at all.
I personally have gotten 40.34 MPG out of my DX sedan, with three people in it, loaded full of luggage for a vacation to go skiing. Oh, yeah, WITH a ski rack on top. Now granted, the car had 75K miles on it, and was only 4 years old at the time. I also took the time to have it aligned, balanced, and I change the oil every 5,000 miles with synthetic., so the car was about as efficient as it could get. I have been driving the car a little more aggressively in the last few years, and it is starting to burn a little oil now, but I still get low 30's (31-33 depending on if the oil compaines are fucking with the gas and oxygenating it in the winter) even now with 219K miles, and daily short-distance commuting.
No, you can't stomp on it up the hills, at every traffic light, or drive like you're playing NASCAR on the PS/2, and on the back sides of hills you pop it out of gear and coast...but I would say it is definitely possible..Remember, the HF only weighs 1800 lbs, my car weighs about 2260, and with the people and gear, I'd guess I added 400 lbs. A skinny dude commuting in an 1800 lbs. HF, definitely possible. Other factors, some mentioned above that can affect MPG:
I think the HF also had 165/13 tires, & all you dudes with fatty 205 or 215 width tires are laying about 45% more contact patch = more rolling resistance = more drag.
I think the HF only has one mirror (stock), which is like you sticking your arm out the window all the time. It isn't much, but think about on a long stretch of highway if we could fold in those mirrors knowing there was no one behind us..it makes a difference.
The tall gearing of the HF allows the car to cruise at 65MPH at about 1900 RPM. Since the motor is only pulling 1950 lbs. down the road, it doesn't need to spin at 3000+ RPM, therefore the engine is running nice and slow and efficient.
So I think it was definitely a possibility. Dude probably didn't get 65mpg ALL the time, but I am sure sometimes he did. Some tanks, I only get 28-29, if I use the A/C a lot, or I am hauling stuff - more recently I towed 1100lbs. worth of boat and gear 365 miles with 3 people in the car, and STILL got 27 MPG. My buddy drove his Suburban with an identical boat, and didn't see his fuel efficiency change at all..he still gets 12-13 mpg regardless

- But I remember him spending about $35 at every gas station, and I spent about $13. I had a lot more leftover for beer money.

All you haters can't underestimate the mighty D-series!!!