well short and sweet, I got the eco bug a decade ago in college. I was very dedicated to a solar powered hydrofoil build (flying electric boat). Switched over to cars because its a hobby/topic you can discuss with other people.
so heres the car list:
99 mercury cougar (2.5l v6 auto). easily was getting 36mpg hwy with it and was topping out in the low 40s.
94 towncar (crushed by govmnt). suprisingly efficient on the hwy. 25 ave, best tank was 31
96 ford contour (same 2.5l v6 but stick and a fair amount of performance work, very sick race tranny). it was a stubborn car, should have been capable of some very impressive eco numbers but just never topped 30.
09 honda fit. have averaged 42mpg for the 6.5k I've had it.... could be alot higher but its there for DD.
anyways, I am someone who tinkers extensively with things. the cougar really is my car passion and something I've taken to the Nth degree. Weight particularly.... if its not required for safely or road legality, its NOT in the car (down to the individual wires, that was over 30 pounds right there).
case in point: