I'm dating myself but in the '60s vehicles with overdrive were the ride of
choice for us California surfers.  There were no 'swell forecasting'
internet sites, so we spent lots of time on the road looking for surf.
 My first surf wagon was a '51 Ford Woodie wagon,  flat head V8 with an
overdrive tranny that got over 25 mpg, going up and down what was Hwy 101,
looking for surf.  These ancient vehicles were getting the same gas mileage
as current cars and they were built over 55 years ago! Our all time best
mileage vehicle was a 53 Buick straight eight with overdrive, owned by one
of my buddies.  That one would take us from Seal Beach to the Trestle (camp
Pendleton) and back on just under a dollar and a half of gas money..We'd get
it rolling through South Laguna and kick it up into neutral at Dana Point
then coast all the way to Doheny beach..
 I traded my Ford 'Woodie' for a 56 Chev with overdrive and no
backseat..That one got 26mpg.  My dad's car was a 55 ford wagon with
overdrive and a V8 (22mpg) .  That technology worked for much better fuel
economy back then and probably still would today.  A lot of vehicles had
overdrive in the 50s and 60s.   It, overdrive, will probably re-appear, when
the gas supply starts to run right out.
  If you are paying attention, you will have noticed some Japanese car
makers are actually advertising fuel efficient cars recently.  Now that the
market 'sucks' for fuel hogs, they've started touting "50mpg.." etc rather
than "how many train cars their full size pickup can tow"  They will build
whatever they need to to make the best profit.  "Green" ads are big, too.
Appealing to the wealthy who can afford to pay for a hybrid vehicle..
  An interesting side note on Europe:  I was watching  the Paris Roubaix
bicycle race recently, a  huge event drawing giant crowds out to the
countryside to party and watch the cyclists and I noticed the European RVs
are all small.  About 20% of the size of what we see on the roads of
America.  I didn't see one that looked to be over about 20' (6 meters) long.
I didn't see many Vanagons, but there were lots of Eurovans and whatever the
Sprinter is copied from.
  Don Hanson