[kgwedi]

I have been driving this month with an extra 20 gallons of water in containers in my Metro.
My driving style is minimum idle, minimum brakes, and pulse and glide with engine off. Extra weight makes my coasting noticeably longer, with a slight increase in power to overcome the extra mass and rolling resistance. If my Metro weighed many tons, it would coast for a long time because aerodynamic drag would be a small percentage of the kinetic energy available.
Bullets are made out of lead (or depleted Uranium) so they go farther for the same amount of initial power than lighter bullets.
If you watch a soaring championship, the gliders carry about 100 Gal. (800pds) of water as ballast. This gives them a better sectional density. CDa/Mass (????)
Doing an A-B-A test with different pulse lengths and coast lengths would be very difficult to get right.
I often read about people removing things to save weight, and here I am adding weight. I feel that my FE is better with the extra weight. What I really need is an extra 600pds to see a definite change.
If extra weight is good for gliders, and bullets, why isn't it good for me and my Metro?
Has anyone done testing to see what real effect extra weight has on P&G and FE?