These non-flammable oils are undoubtedly the most efficient on the market due to their chemical and thermal inertia which outperforms that of the other bases mentioned above.
With variable viscosity indices depending on their structure (linear or branched), these oils cover a temperature range of
-90 to 300°C and enable very long service lives to be achieved even above 200°C without the formation of hard residues that are detrimental to the
the bearings' service life.
Their disadvantage is their cost, which is accentuated by their high density.