bolt is like spring
place spring in "tension" by PRE-LOADING
proper pre-load is dictated by bolt tensile
lubricants reduce friction coefficient at differing rates
lower friction means bolt reaches proper pre-load under LESS applied torque value
the "spring" under tension holds the parts in a JOINT with a range of expansion and contraction within which it will still keep the parts in tension. this is the key.
MOLY's can and DO reduce the torque required to achieve a given tension
good lubes can also help the torque applied to pre-load achieved value to be more consistent, therefore target tension more predictable
appropriate adjustment in applied torque is necessary to prevent JOINT FAILURE.
JOINT FAILURE occurs as a by-product of "LOSS OF TENSION", or compromised pre-load
loss of tension can be caused by vibration, expansion/contraction, bed-in or "seating-in" of the fastener flanges-to-parts in joint... or simply, OVER-TORQUE where the tensile of the fastener is EXCEEDED and it stops acting as a SPRING because it has "fatigued"... and is now "over-stretched"
Using low-coefficient lubes with low tensile fasteners and applying increased torque is a recipe for joint failure.
just some thoughts...
-crisp