The later air cooled engines were horrible in the fuel economy area. They pushed the Diesel engine into service to have something to sell until the waterboxer was ready and the real early water boxers were different from what most of us are familiar with. You now you have a real early one if it had a 180mm clutch and a single groove crank pulley. Anyway from my experience 15-17 is about the best they will do. To be sure that you are getting the most out of it chsck the engine compression-leak down. It is common for these engines to leak at the top of the cylinders where they meet the heads. Burned valves, intake and exhaust and missing EGR components take away from performance and can cause issues. 

Dennis  

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of J B
Sent: Friday, November 23, 2012 7:07 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Fuel econmy and VW Camper Family

We just got back from our trip to San Jose. Was planning on going to a pre-Thanksgiving meet organized by VWCamperFamily which was close by but unfortunately couldn't make it - maybe next year.

Anyway, I had a question as to fuel economy and what I should be getting.  I have read anywhere from 18-25mpg is normal for the air-cooled campers but the best I can get is in the low 17's. This trip got 14.2 with one tank and that was mostly highway at 55-60mph, and the best only 15.5mpg. (81 air-cooled westy)

Also updated my blog, please feel free to take a look http://1981vwcamper.blogspot.com/