Aerodynamics acording to Myth Busters!

On Jul 24, 3:46 am, Stealth Pilot
wrote:
On Tue, 24 Jul 2007 01:42:48 +0000 (UTC),

I tested this one on my own after reading a NASA report about that
locked vortex thingie. Using cruise control only, at 70 mph, out
accross I-70 in western Kansas, both ways to account for headwinds,
etc., ad-infinitum, my 2002 Dakota 4-door averages 1/2 mpg better with
the tailgate up. woohoo. big deal.

The vortex is not a myth though. Wanna guess what happens when a house
painter opens the sliding rear window of his Chevy and then flicks his
butt out of the driver's window? Non-smoker's revenge! Yep, that so-
called vortex grabbed hold of the forest-fire inducing, bar polluting
cancer stick and shot it back inside the truck, under the seat. Where
it did its thing and set his truck on fire a few minutes later in the
parking lot of the local strip joint.

Now here's the real question. If Jamie was using an "aircraft" fuel-
flow meter and it had been "calibrated" to his truck (also a Dodge
Dakota, but a 2-door and I'm guessing a 3.9L V-6), why did it show
something like 5.4. ...5.4 what? They never did say how many mpg
they got with either method. And I've never been able to work out the
math on that number. If its gph, then at 55 mph, thats 5.4 gallons,
devided by 55 miles, equals 9.163 mpg? In a Dak? Only if he's towing a
5k trailer into a 30mph headwind uphill. The 3.9L Dakota should be
somewhere around 18-21 mpg at 55 mph. I can get 19-20 with my V-8.
Could it be pounds per hour? That doesn't sound right either. A gallon
of unleaded is roughly 6 lbs according to BP, or so sez the internet
page I just Googled. So Jamie's truck is getting nearly 60 mpg at 55
mph?

Anyone have any more insight on this?

Harry "saws arm off and hands to gas station clerk" Frey
'02 Dak pusher