The "red stuff" is probably Marvel Mystery Oil or  ATF.  I think the
correct viscosity oil is as, or maybe more important than the filter.  Too
thick and the lifters won't get sufficient oil, too thin and they will
bleed down.  Most of us tend to use oil on the thicker side as the engines
age.  The Vanagon filter will only partially drain, if at all, on
shut-down.  There is some internal differences as to pressure drop across
the filter medium.  Stick with Mann or Mahle and pre-fill on changes--it
can't hurt.  There isn't that much difference in cost.

                                                        Jay '85 Westy