Thinning of the
oil is due to polymer shearing or fuel dilution. Oils with little or no
VII
(Viscosity Index Improvers), such as true synthetics, are not prone to
thinning
from shearing, but will thin due to fuel dilution.
Thickening of oil
is primarily due to evaporation of lighter base stock components, and
oxidation
of the oil. In diesel motors, soot load can also contribute to
thickening of
the oil.
Fuel dilution
is an
indication of mechanical failure, and no filter is capable of removing
it
effectively. Through the use of oils with reduced VII’s and
effective By-Pass Fine-Filtration, viscosity loss and gain can be
reduced or eliminated, allowing
for previously unobtainable extension of the serviceable life of oil.