On Tue, 1 Nov 2016 19:10:39 -0500, Yuri Kreaton
wrote:

how many pounds of thrust does it take to keep 4000 pounds up in the
air, stationary, and then gliding ?

Zero using baloons:
https://www.youtube.com/watch?v=Zy5qUexdMVI
http://mavericklsa.com

If you don't like the baloons:
"4 Real Flying Cars That Actually Fly"
https://www.youtube.com/watch?v=bXuypU5lDsM
"10 Amazing Flying Cars You Won't Believe"
https://www.youtube.com/watch?v=B-uq1Uqp_8g

Sorry. I couldn't find any numbers on gas mileage.
http://www.cessna150152.com/faqs/performance.htm
A Cessna 150 gets 15 to 22 miles/gallon.
My 2001 Subaru Forester gets about 21 miles/gallon.
The difference is wasted fuel while idling, stop-n-go traffic, and an
engine that's not optimized for operating in a narrow rpm range.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558