Go look on any car lot at any gas V8 truck's window sticker. The mileage estimates are about the same as in the 70s. Mid teens for around town and 20 give or take highway. All those fancy electronics and overdrives haven't done a thing.
My buddy bought a '78 fulltime 318 1/2ton,immaculate cond. and 8-10mpg was it! My
'87 Dak. 2wd 8ft. bed got a combined 22.3mpg on a 20gal. tankful,and I was occasionally doin
the extreme miler routine at that.Carb'd 3.9L didn't do bad considering the hills in PA,but.....
The guy that bought the shop I worked previously had an "04 1500 Ram 4X4 xtended cab
5.7 HEMI,22-23mpg on the highway,probably weighed nearly twice the Dak.,3X the HP,and
pulled the same. I tuned My Dad's '76 GMC heavy 3/4 ton to go pick up the '64 GT droptop I
purchased in OK.Bumped timing 3deg.,added clutch fan,195 'stat,tune-up etc. It turned the
best it ever had since He bought it new on the way out,....14mpg,w/tow dolly,tools and
supplies and co-pilot.350 4bbl 4spd.,4.11 gears,235/85LT16 E loads. As much as I love old
school,modern eng.controls and management have dramatically improved perfomance,as well
as increased cost,complexity,repair bills offsetting lower maintenance costs,well,can't have it
all!!! P.S. lying on the window sticker ain't as easy as it used to be!!