Have you ever noticed how light the seat cushions are on an airplane? That’s not by accident.
I once took a short hop from Tampa to Jacksonville FL on a Boing 737 and the plane was nearly empty. Furthermore, since the flight was so short, they didn’t exactly have to top off the tanks with fuel. It seemed like we were off the ground about 15 seconds after the pilot firewalled the throttles. I bet we didn’t even roll a quarter mile before liftoff. We climbed like a rocket.
Boats are also extremely weight sensitive, get rid of all those extra anchors, bilge junk, ropes, etc, and suddenly the old bass boat planes at half throttle again.
It’s a lot of bunk and will be something in which any perceived benefit could never be measured.
If they’re really serious about shaving weight then eliminate the paint jobs on the aircraft and revert to all natural finishes.
The paint on a 747 weighs about 1200 pounds and on smaller airliners can easily run 7-800 pounds.
Of course, that would eliminate those pretty colors and get rid of their advertising canvas…
As to cars, downsize the body and engines, get rid of the bells and whistles, and see how many would choose to live without an electric motor running their windows up and down, driving without power assisted steering, etc.
Jets almost never “fill the tanks,” because then they have to leave paying passengers and/or cargo behind.
Regs require fuel to go from departure to arrival, plus 45 minuts, plus (occasionally) fuel to divert to an alternate. Over and above that is “pilot’s discretion,” and companies are increasingly trying to pressure their pilots in this regard.
(Sounds like a little “full-tank-work-to-standards” might be in order?)