Considering today's "clean" low BTU fuels and your vehicle 22 mpg is a
stretch. Especially if you drive at higher speeds or facing headwinds. 17 is
a bit low but there are many factors that can influence fuel economy
especially on older engines. How much do want to invest on diagnostic to
gain 5%?

Engine compression-leak-down! Is everything being put into the engine
burning and making power?
Ignition timing?
Use the O2 sensor to test mixture control.
Cylinder balance. Disconnect injectors with engine running one by one. Do
all cylinder cause the engine to drop the same RPM when disconnected?

After that check exhaust-catalytic converter.
Choice of tires and wheel alignment.

After all that you pretty much have what you have.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of B
Feddish
Sent: Wednesday, May 02, 2012 1:01 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Still lousy gas mileage

So on my trip north this past weekend I only got 17 mpg on the highway with
my 83.5 w/c Westy. That is my normal city mileage.  I should have gotten at
least 20 if not 21-22.  All the usual suspects have been checked.  if anyone
has any last minute suggestions for me that I can try this weekend let me
know.  Otherwise it looks as though I will have to take it the expensive
mechanic who I know is going to charge at least a few hours and still may
not find something.

Thanks,
Bryan