This is Wentworth parked today, right next to the exit of the parking lot.
Here is everyone else, close to the building, but nowhere near the exit.
I know, I know. This looks like some extreme nutbag case of getting your money's worth for every last drop of gas in the tank. In a small parking lot, well, yeah, that's true :-D. In a large lot like this, if you're interested in upping your mileage, the lesson is to always park facing out right near the exit. Always. No exceptions. Unless everyone starts doing this, in which case I'll have to retract my position so I can get the good parking spaces :-)
You're basically getting around 0 mpg as you wallow around in traffic right near the startup. Remember, miles per gallon can't simply be averaged together. If you get 5 mpg for the first minute as you idle, check your phone, turn on the radio, then slowly progress out, and then get 25 mpg for the next minute when you're driving at speed, you can't say you've gotten 15 mpg ([5 mpg+25 mpg]/2). Those low miles per gallon act very heavily as a weighted average. If math bores you, skip the next paragraph and just read the point below (secondarily, go buy a math book).
If you patter around at 12 mph for a minute, at, let's say, 5 mpg for 0.2 miles, you've used 0.04 gallons of gas. Let's say you manage to go another minute at 35 mph, getting 25 mpg in any number of large, shiny sedans with more horsepower than you can shake your fist at, thus covering 0.583 miles, using 0.023 gallons of gas. Altogether you've covered 0.783 miles on .063 gallons, for a whopping 12 mpg.
The lazy person rundown for scenario outlined above:
One minute at slow speeds getting out of a parking lot = 5 mpg.
One minute driving at 35 mph = 25 mpg.
Total "average" mpg = 12 mpg.
Or(!) park near the exit, get right up to that 25 mpg cruising speed. Sure, you used a little on startup, so let's knock you down to 20 mpg. You can see, though, that you'd be off on your trip already with 66% better mileage (20 mpg versus 12 mpg) when compared to the standard close parker. Gas prices are, incidentally, interested in these sorts of percentages, and will reward you for thinking about them ahead of time.
And that's why you always park at the exit of a parking lot.
P.S. Love this sort of stair stepper action! Bar on far left was accelerating up to highway speeds, yet still above 50 mpg over those five minutes. Next from left is highway, as is the next 75 mpg bar. After that lower speeds for better hypermiling in traffic. Tank is looking good, 66.7 mpg display over 396 miles. Should be low 60s in reality.