Why Synthetic Oils Are Superior
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You may have heard that synthetic oils are superior to conventional oils, that
with synthetic oil cars run cleaner and more efficiently for longer? Would
you like to learn why synthetic oils are superior and discover some of the
benefits you can get from specifying synthetic oils for your car? If so the
information below should provide answers to most of your queries.
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Engine Oil Basics
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Motor oil is more than just old dinosaur bones and prehistoric tree trunks.
It’s the lifeblood of an engine. Motor oil keeps engine parts from wearing
and reduces friction by providing a protective layer between the metal parts
of an engine, and helps carry heat and impurities away from engine components.
Motor oil also has to deal with the harsh operating environment inside an
engine with its combination of heat, combustion by-products, chemical residues
and high pressures. It’s because of this harsh operating environment that
motor oil gradually ages and needs to be changed regularly. Synthetic oils
typically have a far greater resistance to deterioration and therefore have
far greater drain intervals.
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What Is Lubricating Oil?
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Motor oils are made up of selected base oils combined with performance
enhancing additives. Why are additives required?
• Additives improve the original properties of base oils
• Additives impart new performance characteristics to base oils (to suit
particular applications)
• Additives help extend the product life
Motor oils
typically are 75-85% basestock with the balance being additives. That’s why
basestock quality is such a critical contributor to the performance of the
final blended product. You’ll find out more about additives below.
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There Are Four Different Types of Motor Oil Base Stocks
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We know that basestock composition has a significant effect on the overall
performance of motor oil. There are four different types of base stock used
in the motor oil market today.
Group 1 - Conventional - Mineral oil derived from crude oil
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
Group 4 – Full synthetics (chemically derived) - Chemically built
Polyalphaolefins (PAO).
As it infers Groups 1 – 3 basestocks are derived from crude oil pumped from
the ground whereas Group 4 basestocks are chemically derived, most often from
ethylene gas, and contain none of the contaminants present in mineral oils.
Just as distilled water is pure water derived from gas so Group 4 basestocks
are pure oils derived from gas.
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And There Are a Variety of Additives
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Additives enhance the performance of motor oil basestocks and help adjust the
performance of the oil to suit its intended application. Additives are the
key to unlock the performance potential of basestocks but even the best
additives won’t turn bad oil into good oil.
Some common additives include:
• Viscosity Index Improvers – improve ability to handle heat and severe
conditions
• Pour Point Depressants – lower oil freezing point in cold conditions
• Anti-wear Additives – protect against metal-to-metal contact
• Detergents & Dispersants – keep components clean and prevent sludging
• Oxidation Inhibitors – maintain oil stability over service intervals
• Corrosion & Rust Inhibitors – protect against the effects of condensation
• Defoamants – prevent oil foaming and cavitation
Additives work symbiotically with the base stock and are added in different
proportions according to the application. Some examples are that racing oils
may not require rust inhibitors but could need extra defoamants for dry sump
oil systems, domestic or consumer engine oils may need special additives that
don’t interfere with the operation of catalytic converters or diesel oils may
require additional protection against combustion byproducts.
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Let's Look at Conventional (Mineral) Oil
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Conventional motor oils use base stocks created by the conventional refining
of crude oil pumped from the ground. Crude oil is a complex mix of
hydrocarbon compounds and a variety of sophisticated refining techniques are
used to remove/reduce the amount of undesirable components such as asphalts,
waxes and chemically unstable sulphur & nitrogen compounds. Conventional
motor oils use conventional mineral base stocks so are usually known as
Mineral oils.
Mineral base oils have performance limitations. After refining what remains
is a lubricating base stock that despite the degree of chemical refinement
still contains undesirable materials such as oxygen, sulphur, nitrogen
compounds, trace metals and carbon residues.
There are literally thousands of compounds present in crude oil. While many
of them are removed or upgraded by refining, a significant concentration of
these undesirable materials remains in lubricating oil base stocks. These
residual undesirable materials mean additive packs can’t operate to full
effect because the additive has to compete for space with the impurities when
they attempt to bond with the baseoil molecules. Consequently the molecular
structure of the oil is inconsistent, limiting the performance capabilities
and useful service life of the resulting blended oil.
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Hydroprocessed Oil
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Hydroprocessed motor oils use base stocks made by the additional refining of
mineral oil. While refined to a greater extent than conventional mineral base
oils, hydroprocessed base oils still have similar performance limitations due
to the presence of undesirable impurities which cannot be completely removed
from crude oil. Hydroprocessed motor oils use extra refined mineral base
stocks.
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Severe Hydroprocessed Oil
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Severe hydroprocessed oils are further refined hydroprocessed oils but they
still contain some undesirable impurities which cannot be completely removed.
Most engine oils on the Australian market advertised as synthetic use severe
hydroprocessed basestocks.
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Semi-Synthetics
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Semi-Synthetics use base stocks comprising conventional or hydroprocessed base
oil in combination with severely hydroprocessed or synthetic (PAO) basestocks.
The proportion of severely hydroprocessed or synthetic basestocks in
semi-synthetic oil is a closely guarded secret, but is usually between 10% and
25%.
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Synthetics
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Synthetic motor oils contain a high proportion of base stocks created from
pure chemicals. Since synthetic base stocks such as PAO are essentially pure
chemicals themselves they avoid the performance limitations imposed by the
impurities present in conventional and hydroprocessed base oils. PAO synthetic
base oils are therefore pure compounds containing none of the impurities found
in conventional base oils derived from crude oil, as mentioned earlier.
In addition, chemically derived synthetic base stock technology allows the
base oil molecules to be designed specifically for particular lubrication
applications with purpose designed features such as the exact desired
viscosity, superior viscosity stay in grade capability, low volatility etc.
Synthetic base stocks can also be specifically tailored to suit different
additives required for different applications. Additionally because synthetic
oils are ‘pure’ they contribute lower emissions and are kinder to catalytic
converters. Synthetic oils can also be engineered to have less internal
molecular friction allowing an engine to develop maximum power and provide
best possible economy.
Synthetics can therefore be "tailored" to suit specific lubrication
applications. The molecular engineering that goes into chemically derived
synthetic base stocks enable a base oil to be designed for a specific purpose.
For example specific base oil molecules have been designed for use in Mobil
Jet Oil II (which is used by 70% of the world’s commercial jet aircraft).
Similarly and very specific Mobil 1 formulations have been designed for
Formula 1 racing applications. This same highly specific molecular engineering
approach has been used to design the best base oil molecules for use in
consumer synthetic motor oils such as Mobil 1.
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Base Oils Summary
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Mineral & Hydroprocessed Base Oils
• Refined from Crude Oil
• Mixture of compounds
• Include compounds poorly suited for lubrication
Chemically Derived Synthetic Base Oils
• Synthetic polymers
• Tailor made from controlled building units
• Specifically designed to suit the lubrication application
Unlike base oils derived from crude oil, synthetic base oils can be designed
specifically (i.e. "tailor made") to give optimum performance in synergy with
the additive compounds with which they are formulated to produce the final
motor oil.
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So What Does This Mean to You?
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Motor oils perform differently under extremes. Under extreme driving
conditions synthetic oils offer clearly superior motor oil protection and
performance than that provided by mineral oil.
Severe conditions include;
• Stop-and-go driving
• Short trips
• High temperature conditions (especially modern turbo engines)
• Cold start-ups
• Competition
Severe driving conditions aren’t confined to the racetrack or rally stage.
Day-to-day driving conditions with stop/start traffic, short trips and cold
starts can also be severe conditions that push motor oils to their limits.
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There Is a Clear Difference in Motor Oil Protection and
Performance
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What are the differences?
Differences under extreme conditions:
• Conventional (mineral) Motor Oils break down under extreme hot temperatures
and form solids under extreme cold temperatures.
• Hydroprocessed Motor Oils and Semi-Synthetics vary depending on their
composition, but generally perform better than conventional (mineral) formulas
but not as well as full synthetic oils.
• Fully Synthetic Motor Oils offer the maximum protection against engine wear
under extreme hot and cold temperatures and in other severe service
conditions, unmatched by conventional or hydroprocessed formulas.
Fully synthetic motor oils offer the best engine protection and allow an
engine to develop its maximum potential, leading to increased power and
improved economy when compared to equivalent mineral oils.
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How Do You Make the Best Oil?
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You start with the best fully synthetic base stock chemically engineered for
optimum lubrication and keep adding to it. Tailoring the additive packs
allows the components of the finished oil to be optimally balanced resulting
in the best formulation.
While other manufacturers buy off the shelf additive packages, Mobil 1 is
formulated from over a dozen individual premium components. This component
approach maximizes performance under all driving conditions, providing the
highest level of engine protection available. The make up and proportions of
these individual components is continually reviewed and updated to maintain
the position of Mobil 1 as the best engine oil you can buy, as it has been
since it’s inception in 1973. Mobil’s proven synthetic experience over more
than 30 years overcomes potential problems such as seal swelling and poor
solvency/detergency, which have been experienced with some other brands of
synthetic oils.
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Then You Run Rigorous Tests
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ExxonMobil engineers put Mobil 1 through the most comprehensive tests in the
industry to ensure that its performance far exceeds worldwide standards. Not
just once but over many repeated cycles.
Some of these tests include:
• Cold Temperature Pumpability (Pumping Temperature Limits)
• High Temperature Stability (Sequence IIIG Oxidation Test)
• Low Oil Consumption (Noack Volatility Test)
• Fuel Economy Testing
• Extensive Performance Reserve Testing including
• Extended length engine testing
• 25,000 mile oil drain testing
• Low mileage no drain performance testing
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Mobil 1 Temperature Properties
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Mobil 1 Cold Temperature Properties
Mobil 1 has outstanding low temperature fluidity (it will flow at temperatures
below -54°C) and allows the cold starting potential of any car to be
maximized. Most engine wear occurs during the critical first seconds after
start before the lubricant flows into place to prevent direct metal-on-metal
contact. At all cold start temperatures synthetic oils get to the critical
wear areas (camshaft & bearings) of the engine quicker than equivalent mineral
grades.
Mobil 1 Hot Temperature Properties
So what value is this at high temperatures? At high temperatures the oil
molecule in synthetic oils are far more stable and degenerate less. This means
not only do synthetic oils maintain lubrication integrity, they continue to
cool and clean engine components at constant temperatures of up to 180°C, and
can handle short term temperatures in excess of 200°C.
At Bathurst in 2002 when the winning HRT Commodore was running with a blocked
radiator inlet the oil temperature rose to above 200°C yet the engine not only
survived in perfect condition, it won the race.
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Racing - the Ultimate Test
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The extremes of competition place enormous demands on an engines oil and
leading teams rely on synthetic oils to give them the edge in performance and
protection.
• The Formula 1 McLaren Mercedes, Ralliart WRC and Holden HRT teams use
synthetic engine oil because a mineral oil simply would not work under the
extremes of competition
• Only a fully synthetic oil can provide the anti-wear & high temperature
protection required in competition applications
• The use of Mobil’s latest synthetic technology provides horsepower benefits
in addition to exemplary engine protection and cleanliness
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OEM Applications
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Because synthetic baseoils can be tailored to suit specific applications and
because of the consistently high quality of synthetic oils many manufacturers
of high performance cars specify Mobil 1 to achieve specific requirements for
performance potential, drain intervals, fuel economy and emissions compliance.
Consequently Mobil 1 is the factory fill for many of the world’s finest
high-performance automobiles including:
• Porsche
• HSV
• Mitsubishi EVO
• Mercedes-Benz
• Dodge Viper
• Chevrolet Corvette
• Cadillac
• Callaway
• Lotus
• Aston Martin
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Other Applications
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The benefits of Mobil’s synthetic expertise extend further than engine oils.
The same synthetic technology is applied to gearbox, differential/final drive
assemblies and wheel bearing and chassis grease (Mobil SHC series).
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Which Synthetic Should I Use?
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Always consult manufacturer specifications to determine which type of oil
should be used. The Mobil Technical Response (Aust: 03 9205 3222 or freecall
1800 033 863, NZ: freecall 0800 732 275) Line will be able to assist you with
application and usage information. The condition of the machinery will also
determine to some extent which oil to use.
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