1) These DRIVING TIPS will do more for you than filling station tips;
http://www.fuelly.com/tips/

2) And of course you should tune up your van, keep it healthy and ensure all
systems are happy.

3) Lastly, keep a log of your mileage/fills so you can see when performance
changes.  If it goes down significantly, see step 2.

Jim A. and others in the Vanagon community use this free website to share
their results...and make pretty charts.
http://www.fuelly.com/car/volkswagen/vanagon

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