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Why Motor Oil Deteriorates
It is common knowledge that, at some point, engine oil must be changed.
It’s something that is preached relentlessly to vehicle owners by vehicle
manufacturers, quick lubes and oil companies. But consumers are widely
unaware of what exactly makes oil changes necessary. Many factors
contribute to a motor oil’s demise, but it is essentially the accumulation
of contaminants in the oil and chemical changes in the oil itself that make
a motor oil unfit for further service. With time, it is inevitable
that the oil will be contaminated by dirt or sludge, or succumb to the
extreme pressures or temperatures found inside an engine. AMSOIL Motor
Oils are formulated with the industry’s most advanced synthetic base stocks
and additive packages to combat the forces that deteriorate conventional
oils.
Extreme Heat
Today’s engines are running hotter than ever. More horsepower, turbo
chargers and aerodynamic styling have created extremely hot environments
that receive less cooling from outside air. High heat leads to oil
oxidation, deposits and thickening in conventional oils. Because they are
made from impure, irregular molecules, conventional motor oils are more
susceptible to the effects of heat. The small, light molecules in
conventional oil tend to evaporate as the oil is heated, leaving large,
heavy molecules behind and leading to oil consumption and an increase in the
oil’s viscosity. If those large, heavy molecules are chemically
unstable, they may also break-down and form deposits on component surfaces,
further inhibiting the release of heat into the oil stream. Even in
relatively mild temperatures, oxygen works to break down some of the
chemicals in conventional lubricants. The extreme heat in engines
actually promotes oxidation. When conventional oil contaminants break
down, they coat components with varnish, deposits and sludge and leave the
lubricant thick, hard to pump and with very poor heat transfer ability.
Extreme Cold
Cold temperatures cause oil to thicken. Conventional lubricants
contain paraffins which cause them to thicken in cold temperatures as the
paraffin gels. At startup, this can leave working parts unprotected
for as long as five minutes while the oil warms to a temperature that allows
it to flow.
Common
Contaminants
Dust and dirt from the air enter the engine through faulty air cleaners,
some oil fill caps and crankcase ventilation systems. Normal engine
wear produces small metal particles that are picked up and circulated by the
oil. The abrasive particles of road dust and dirt increase the rate of
wear and generate larger metal particles. Those particles are equally
abrasive and the rate of wear accelerates with a snowball effect.
While filtration removes most of these contaminants, some remain and are
left to circulate with the oil.
Combustion Byproducts
Combustion produces several byproducts that also act as contaminants.
Water and acids lead to sludge, rust and corrosion. Soot and carbon
create sludge and varnish and can clog filters. Unburned fuel in
liquid form is deposited on cylinder walls where it leaks past the rings
into the crankcase. Sludge deposits collect on oil pump screens,
limiting the flow of oil to vital engine parts and resulting in rapid and
destructive wear. When oil becomes contaminated, it’s viscosity
changes. With soot, dirt, oxidation or sludge, viscosity increases;
with fuel dilution it decreases.
Internal Forces
Engines create a great deal of internal pressure. Extreme pressure can
result in boundary lubrication which breaks the oil film between moving
parts. Movement inside the engine agitates the fluid, trapping air and
forming bubbles or foam. Because air is compressible, the ability of
the fluid film to prevent contact is reduced. And because the mixed
air contains oxygen, it promotes oil oxidation.
Additives
Careful research and experimentation led lubricant manufacturers to specific
chemicals that combat various problems faced by motor oils. These
chemical additives are added to base oils as a package. Typical
additive packages can include rust and corrosion inhibitors, detergents,
dispersants, antifoaming agents, oxidation inhibitors, extreme pressure
additives and viscosity index improvers. Each additive is designed to
aid the base oil in the protection of components, but additives have their
limitations. While these additives are created to perform specific tasks,
they are also subjected to the same extreme environment experienced by the
base oil, and each additive is affected by different variables in different
ways. For example, viscosity index improvers are used to reduce the
thinning effects caused by operation at elevated temperatures. They
are the key components that allow for the production of multi-grade oils.
However, the long molecules in viscosity index improvers are subject to
shearing in service, which reduces their ability to minimize fluid viscosity
loss. Permanent shearing of viscosity index improvers can result in
piston ring sticking due to deposit formation, increased oil consumption and
accelerated equipment wear. High quality additives perform best and last
longer when paired with high quality synthetic base oils.
It’s All in the Molecules
Conventional lubricants are made from refined petroleum, a naturally
occurring and impure substance. The varied and non-uniform size and shape
of the molecules that make up conventional oils lend themselves to
contamination. They cannot withstand extreme heat or cold, and they
burn off and succumb to oxidation, leading to the development of deposits
and component wear.
AMSOIL Synthetic Motor Oils are Superior
AMSOIL Synthetic Motor Oils provide extended equipment life, reduced
maintenance costs, better performance, improved fuel economy and extended
drain intervals through the use of high-quality synthetic base stocks and
superior additive packages. Because they are derived from pure chemicals,
synthetic lubricants contain no unnecessary molecules. Their smooth
lubricating molecules slip easily across one another, improving the lube’s
ability to reduce friction, which in turn improves wear control, heat
control and fuel efficiency. In addition, uniformly sized synthetic
lubricant molecules resist thinning in heat and thickening in cold,
decreasing the need for viscosity index improvers and increasing the lube’s
ability to maintain its viscosity. Because AMSOIL synthetic lubricants
contain only strong, uniform molecules, they are much more resistant to
thermal and oxidative breakdown. AMSOIL synthetics are virtually
impervious to breakdown at normal operating temperatures and can be used in
higher temperatures than conventional oils without breaking down. AMSOIL
Synthetic Motor Oils keep components free of varnish, deposits and sludge.
 The
NOACK Volatility Test determines the evaporation loss of lubricants in high
temperature service. The more motor oils vaporize, the thicker and heavier
they become, contributing to poor circulation, reduced fuel economy and
increased oil consumption, wear and emissions. AMSOIL Synthetic Motor Oil
resists high temperature volatilization better than other motor oils.
AMSOIL Synthetic Motor Oil maintains peak fuel efficiency and reduces oil
consumption and emissions.
Extended Drain Intervals
Not only do AMSOIL Synthetic Motor Oils provide protection that is superior
to conventional oils, but they remain fit for service many times longer as
well. Heat and oxidation are the main enemies of lubricant base
stocks. The excellent resistance of synthetic lubricants to thermal
and oxidative breakdown allows them to be safely used for much longer drain
intervals than conventional lubricants. Their uniform and smooth
molecular structure allows AMSOIL Synthetic Motor Oils to operate with less
friction and better heat control than conventional lubricants.
The Choice is Clear
When AMSOIL motor oil was introduced in 1972 it was ahead of its time.
Today, engine designers have goals of increased fuel economy, reduced
exhaust emissions, more performance out of smaller engines and greater
durability, increasing the demands placed on motor oils and requiring
continuous upgrades. AMSOIL remains at the forefront of the engine oil
market by continuing to provide oils that are ahead of their time. No
other motor oil is guaranteed for 25,000 miles or one year in normal
service, and no other motor oil can match the performance and protection
provided by AMSOIL Synthetic Motor Oils. |
