The original point here  was the vanagons' lack of time for the fuel to mix
with the air before ignition. The slant six has months for this to happen
with an intake runner almost 2 feet long. I am wondering if this lack of
time can be overcome with acetone. Will  acetone atomize the fuel earlier
and give the mixing thing more time to happen? If so, better gas mileage? I
am assuming that acetone  will not make much difference in a slant 6 as the
fuel already has  much time to atomize and mix before combustion.That is
all. My 65 valiant wagon had a slant six w/3 on the tree. I bet many here
dont know what that was. It gave the previous owner 17mpg and I got
17mpg.My 66 econoline w/"boss 170"(geared very low,100hp) six cylinger and
automatic got 17. Not bad for a big flat front end.My 82 fairmont got about
19 mpg w/200 inch six and sutomatic. My friends 77 rabbit got 35mpg with 4
people on board, but that was too new a car for me at that  time.I was a
slant  6 fan too, but it is interesting that of all the six cylinder
engines of the 60s' only the AMC 232 still is made( at last check).Also it
is interesting that chrysler dropped the slant 6 about the time that they
bought AMC. I think the slant 6 weighed more than a small block chevy.
During its first year of existance , it was made of aluminum.These are a
prize today.Long live the Pacer!  I wondered if the link provided last week
in "fuel additive" will show a corelation between type of intake manifold
type, and improvement in gas mileage. Or throttle body injection vs port
injection. I do not know which cars tested in the link had these different
types of features, and what mileage improvement , if any , they got.Maybe
some knowlegable person can review these and see if any link exists.