At 07:16 AM 10/21/2009, Dave Mcneely wrote:
>Wind and elevation both make a significant difference for my '91 VW
>Vanagon GL Campmobile 4-speed manual.

Yeah, wind and elevation make a big difference for my '84 Westy.  I
have a GoWesty 2.3L engine with an original 4-speed manual transmission.

I have complete mpg data since I bought my Westy in April:

http://www.fuelly.com/driver/sbw/vanagon

The average over about 13,000 miles, 18.7 mpg, includes about 500
miles with the old worn-out engine, which never got over 16 mpg.

The GoWesty engine is down around 17.3 mpg when I'm hauling stuff around town.

It routinely gets 19-20 mpg near sea level when I drive on the
freeway at a consistent 65 mph, except when it was having problems
with the AFM and a clogged fuel filter.  (Also, I was going 75 mph a
lot of the time in mid-June on the way east.)

Once we got everything dialed in, it jumped up to just over 20 mpg on
the way back west at 65 mph.  On one leg over high terrain in New
Mexico, some of it at lower speed limits, we got just over 22 mpg.

But in high headwinds or crosswinds, it's back down to 17.5-18.5 mpg.

As an experiment, I drove 79 miles at sea level at 60 mph when I knew
there would be no traffic.  On that leg, I got 20.4 mpg.  That's not
far above the best mpg I see at 65 mph, so it seems the optimum speed
is right around 60-65 mph.