Looking for better fuel milage

GENTLEMEN PLEASE.... Scores of highly trained engineers with seriously sophisticated equipment at each of the Auto companies have been facing this issue for YEARS!!!! Which is why cars of today all look like "jelly beans" and have 4 & 6 cyl engines that REQUIRE thousands in equipment to run correctly, only a few 8's are even left out there and even they have gobs of modules running them to meet cafe standards. The ERA of cars we all love was an ERA where for ooodles of years premium fuel was far less than a dollar. ZERO consideration was given to "efficiency" and primary focus was directed at power & speed...remember the quote " whom ever won on Sunday at the races, that manufacturer would sell BIG on Monday!" That was the AUTOMOTIVE BATTLE CRY to gain market share!!! The early narrow A's weighed in around 2700 lbs the newer Dusters weigh in around 32-3300 ( with V8's of course)....these were some of the lightest most powerful vehicles made in those years ratio wise (HP to weight) fact is you are never going to reach 20+ miles to the gallon even in these light weight powerhouses.....they are diametrically opposed attributes for this era vehicle. Back in 72 with a 68 spec'd 340 and using a 850 thermoquad the MOST milage I was ever able to squeeze out of my 340 w/355 gears was 10.1 mpg and that was driving like grandma and never exceeding 50 mph on the highway...... rule of thumb: 60's & 70's high performance vehicles LOVE FUEL! AND THE MORE "performance " goodies that were added typically dropped the MPG vs increasing it.
With premium gas hitting $4 per gallon I am quite contented to bop around town and hit the local shows within 50 miles.....the cross country POWER TOUR aint even on my menu at these prices......so if y'all are basing if ya go or NOT on the MPG of your car......the old saying applies..."if ya have to ask how much....ya can't afford it"
I already KNOW I can't afford it unless I plan on driving a "smart car".....
just my 2 cents