On a 6,099 mile trip this Summer in our 84 Westy 1.9 4spd we averaged
19.46mpg.  60% two lane highways, 30% Interstates, 10% city driving.  The
van was loaded to the gills with people, bikes, and equipment including a
large dry bag spanning the width of the luggage rack area which sticks up
about 14" and doesn't help the aerodynamics any.  Michelin MXT tires,
44psi front, 48psi rear.  I am no speed demon so 60mph was usual cruise,
often lower, sometimes higher.  Air temperature was hot, typically
90-100F most of the time.  Highest realized mpg between fills was 21.98,
lowest was 16.93, which truly goes to show you that "Your mileage may
vary."

Best wishes,

Tony

Anthony L. Mourkas
Hampden, Maine, USA
1984   Vanagon Westfalia
1986.5 Quantum Syncro Wagon
1991   Jetta Eco Diesel