Robin,

What do you mean by "power starved VDubs" ?  I recently took a trip MN-CA
at the legal limit of 75 mph, except with strong cross or head winds, or up
the mountains.  When my son took a turn at the wheel, it is rumored that 85
mph was obtained.
Overall we got 18 mpg.

As far as non-Interstates are concerned, they are frequently more scenic,
but do typically require more attentiveness due to crossroads, hills and
curves. slower vehicles (like our beloved older splitties), and the
occasional desire to pass same.

If you travel the wide open spaces of the West, the two laners have much
less traffic in most places, but that is not the case for the rest of the
country (or Canada).

Traveling from Madison, WI to Cape Cod is much faster along the toll roads,
but you could take U.S. 20 for almost the entire route.  It is more
interesting, but MUCH slower.  Alternatively, drive at 60-65 mph on the
interstates, and stay in the right lane.

Whatever you choose, enjoy the journey.  Do it the way that works best for
you.  Why not take out the old Rand McNally beforehand and figure out
several alternate routes.  Then take whichever suits your fancy during the
trip.

Have fun!

Budd Premack
86 Syncro, 84 Vanagon (for sale)
73 Super
Minneapolis, MN (Land of Sky-Blue Waters)