  The influences and consequences of toroidal magnetic fields in shaping the
visible lobes of pre planetary nebulae ("prePNe") are explored in this, the
last of a series of papers of parameter studies of prePN evolution. To probe
these influences we start with the steady, diverging, and field-free wind model
of our previous papers and add weak to moderate toroidal fields to the winds in
order to generate arrays of outcomes after 500 y, after which the structures
grow almost homologously. As expected, toroidal fields in the stellar winds
invariably form very thin and dense axial features whose structure is best
described as a thin cold jet with an ultra-dense and neutral leading knot, or
"bullet", at its tip. The speed of the leading knot depends only on the density
contrast (the ratio of injected to ambient gas densities at the nozzle) and
wind injection speed, but not on the field strength or opening angle. The lobes
formed by the ram pressure of the winds take a variety of forms and sizes that
depend primarily on the geometric structure of the injected gas and the density
contrast. About 20% of the HST images of prePNe show the unique signatures of
shaping by toroidal fields. Pairs of low-ionization knots seen along the major
axis of fully ionized PNe, often called "FLIERs" are easily explained as the
very dense, cold , and neutral remnants of magnetically formed knots.
