use. The advantage of race oils for
performance engines is their high con-
centrations of anti-wear additives, such
as zinc, phosphorous, and molybdenum.
The Driven race oil listed in this testing
is intended for competition engines,
so it also has relatively low detergent
levels to allow the anti-wear additives to
do their job to protect internal engine
components. Competition engine use
assumes that the oil will not experi-
ence long drain intervals because of the
level of maintenance required of a race
engine. Note also the higher concen-
tration of molybdenum, which is an
expensive friction modifier.
As another example, the Mobil 1
race oil employs ZDDP concentrations
above 2,000 ppm along with lower
detergent levels with a calcium count
that is half that of a typical SN oil and
the same for the Valvoline race oil. The
Mobil 1 oil is similar to the Driven race
oil in that it also radically increases the
molybdenum additive count.
One oil that is certainly unlike all
the rest in this evaluation is the Aero
Shell 15w40. This oil is intended for
piston-powered aviation engines that
have an ashless oil standard. This is
intended to reduce carbon deposits in
the combustion chamber. This demands
the elimination of most detergents.
Obviously, these engines will also
require much more frequent oil changes
because, except for a 1,342 ppm count
for phosphorous, there’s not much else
in this oil and certainly not something
that should be considered for road use.
Testing
Shell’s non-
detergent w
reveals there
is literally
nothing in
it. According
to Driven’s
Lake Speed,
Jr., older non-
detergents
retained
high levels
of zinc and
phosphorous
(ZDDP). With
zero ZDDP
additives or
friction reducers, this oil should not be
used for any automotive application.
12
The additives evaluated in this story
should not be construed as the only
additives in a given engine oil. Beyond
the chemicals listed here, there are also
pour point depressants, viscosity index
improvers, corrosion inhibitors, seal
swell agents, dispersants that prevent
the formation of sludge, and foam
inhibitors. All these combine into a
total additive package that works to
enhance the engine oil’s primary job of
lubrication and cooling.Hopefully we’ve added a little some-
thing to your knowledge of engine oil
and with that an appreciation for the
complex art of balancing the engine’s
needs with the right concoction of
chemicals to satisfy an increasingly
complex set of
requirements. It
also appears that
old Valvoline ad
had the right
message.SPEEDiagnostix
704.795.8828
speediagnostix.comSOURCES: