I havent driven a new vehicle for a few years, During My highschool years I had a daile 36mile commute, useing the family car, a 1972 Poniac Catalina, auto trans, 400cid eng 4barrel carb, Could commute all week on a tank of gas which heald like 16gal of gas, I'd still have a 1/8tank left over at the end the week, its best milage at cruse speed was 67 to 70mph (sweet spot)
Later on had a 1977 350cid Chevy Montie Carlo that did 19mpg on the highway when tuned up. I knew a classmate with a 1974 Chevy Montie Carlo that did even better than that, his car had a economy gage right on the dashboard.
Economy gage was a manifold pressure gage that had a green arc that showed when you were rideing the throttle and wasteing gas.
simple thing like that its ashame one isnt on new rigs.
My favorite frugal work truck was a 1980 4x4 Ford F150 with a 300cid engine and manual tranny.