Here are my results:

If you reply, please describe what the conditions your averages are obtained
under, and grade of fuel etc.
Feel free to cut and paste for a uniform response protocol that will be easy
to compare others to.

Name:

What: 1990 Carat 4spd 2.1l

Drivetrain: New VWoA (Canada) rebuild, new water pump and plumbing, New fuel
lines, VW remanufactured transmission with upside down linkage so that the
reverse lights will never work, won't go into second when cold, and Slick-50
GL-5 lube eating away at the bronze synchronizer rings

Other engine stuff: Rotella T 15W-40 oil; unknown AFM, Cat, and O2 sensor
(could be original), new distributor, plugs & plug wires (traditional
Bosch), New muffler, new air & fuel filters

Tires: Michelin MXT, 40 psi

Extra load carried: About 600 pounds of passengers and cargo.

Speed:consistent cruise of 65 to 70 mph (speedo); 4k on tachometer

Fuel type:We run 87 octane (r+m/2 method) all the time (and try to pick
decent brands if that matters!)

Fuel treatments: usually one bottle of Techron per oil change run through
the gas.

Terrain: on relatively moderate terrain

Other weather factors: calm winds, 98 degrees F, 90 % r.h.

Highway MPG: We get only 17.5 on the highway with the AC on in the summer.

Under load:

Added notes: I can't wait for winter to see how it does.

City mpg:  Most of the van's driving this summer with the ac on has been
around town, lots of idle time, terrible conditions.  We only get 14.5 to
15.5 in this situation!  :-(

Comments: I am really dissapointed in the gas mileage on the "new" engine.
I realize that around town with the ac on is the worst possible condition,
but I was hoping for better than 15.  I know that I could replace the O2
sensor, but the emissions numbers are still good!   The AFM and other
digifant curiosities seem to be working perfectly.  (I am fortunate enough
to have a mechanic who drives a Vanagon and knows how to use an emissions
tester).  My only complaint is that when the engine is cold and I have the
ac on, you have to rev it up really high and let the clutch out slowly to
prevent the engine from dying.