Reference tells us that the precessesion of Mercury *advances* over
time. `The effect is small: just 42.98 arcseconds per century for
Mercury; it therefore requires a little over twelve million orbits for a
full excess turn'
[Moderator's note: The precession is much larger. The figure you
mention is the excess which GR can explain but Newtonian theory can't.
-P.H.]
Does this advance equate to any anomalous decrease or
increase in orbital speed of mercury as it moves away from its perigee.
A change not predicted by Newtonian mechanics? In other words does
Mercury gain or lose speed excess to that expected at perigee?