WHY HARLEY OWNERS CHOOSE AMSOIL BEST
Wear Test Comparison - AMSOIL vs. Harley Screamin' Eagle
The recent introduction of Screamin' Eagle® Synthetic Lubricant by Harley Davidson® indicates the Motor Company
has finally recognized the benefits of running synthetic motorcycle oil in their air-cooled engines. After years of
advising dealers and customers to avoid using synthetic oils in their bikes, it's natural to wonder why the company
is suddenly marketing one.
For the past 20 years, Harley-Davidson® has claimed its petroleum-based Genuine H-D Oil is best for the "unique
requirements of Harley-Davidson® air-cooled V-twin engines." However, laboratory testing has consistently revealed
that Genuine H-D Oil does not provide the best protection possible for Harley-Davidson® engines. In fact, Four-Ball
Wear Tests show Harley-Davidson® 20W-50 Motorcycle Oil leaves a wear scar over 50 percent larger than that left by
AMSOIL Synthetic 20W-50 Motorcycle Oil.
The Smaller the Wear Scar, the better
Four Ball Wear Test
(ASTM 4172), 40 kg pressure
@150 deg C, 1800 RPM for 1 hour duration.
|The four ball wear test is the industry's standard test
method for measuring the wear preventive characteristics of a lubricant, three fixed steel
balls are put into contact with a fourth ball in rotating contact at preset test conditions.
Lubricant wear protection properties are measured by comparing the average wear scars on the
three fixed balls. The smaller the average wear scar, the better the
One of the major benefits of running a synthetic motorcycle oil is its resistance to oxidation and thermal
degradation, which inhibit the formation of sludge and deposits that contribute to increased wear. In the past,
Harley-Davidson® has defended use of its Genuine H-D Oil by arguing that oil breakdown in extreme heat is a
non-issue because extreme heat conditions are not normally faced by motorcycle engines, while the superior
cold-temperature benefits of synthetics also don't apply to Harleys.
The fact is. engine oil in Harley-Davidson® motorcycles is subject to very high temperatures. Being air-cooled,
Harley-Davidson® engines get especially hot while idling in traffic, commonly reaching temperatures up to 240
degrees Fahrenheit. As heat and oxidation increase, so does viscosity, adversely affecting the lubricating
qualities of the oil and increasing wear.
The water, soot and acid byproducts of combustion also contribute to deposit formation. Harley-Davidson® has
stressed the importance of regular oil changes in order to remove these contaminants. Of course, promoting regular
oil changes is also a good way to promote using petroleum-based Genuine H-D Oil. High-quality synthetic oils
formulated with high-performance additives effectively withstand such contaminants, allowing motorcyclists to
safely extend drain intervals.
In support of their about-face and the introduction of a synthetic oil, Harley maintains that "the Motor Company
has never supported the use of synthetic products in our vehicles because there has never been any test validations
completed on the numerous formulations in HD/Buell motorcycles. This product has been exclusively designed for
Harley-Davidson® and is the only synthetic product TESTED and CERTIFIED by Harley-Davidson® engineering for use in
Although this is necessary marketing hype, Harley-Davidson® V-twin air-cooled engines are not unique in their
lubrication requirements and do not require a special Harley-only fluid. There is nothing about Screamin' Eagle®
Synthetic Motorcycle Oil that sets it apart from, or makes it better than, many other synthetic motorcycle oil
formulations, except that Harley-Davidson® is marketing it and directly profiting from the sales.
According to Harley-Davidson®, one of the unique benefits offered by Screamin' Eagle® Synthetic Motorcycle Oil is
its versatility. For the first time the company is recommending an oil that can be used in the engines, primary
chaincases and transmissions of most Harley-Davidson® motorcycles, including Evolution XL, Evolution 1340, Twin Cam
88 and 88B, Revolution and Buell models. This feature, however, is not unique. AMSOIL 20W-50 Synthetic Motorcycle
Oil may also be used in the engines, primary chaincases and transmissions of these applications, providing superior
lubricating protection in each component.
How does Screamin' Eagle® Synthetic Motorcycle Oil measure up to AMSOIL in wear protection? Four-BallWear
Test results indicate that AMSOIL Synthetic Motorcycle Oil still provides the best
protection possible for motorcycles. In fact, Screamin' Eagle® Synthetic Motorcycle Oil leaves a wear
scar nearly 80 percent larger than AMSOIL 20W-50 Synthetic Motorcycle Oil.
Not only does AMSOIL Synthetic Motorcycle Oil offer greater wear protection than
Screamin' Eagle© Synthetic Motorcycle Oil, it also delivers greater value. Suggested retail price of Screamin'
Eagle® is nearly $2 a quart higher than AMSOIL 20W-50 Motorcycle Oil. And because AMSOIL Synthetic Motorcycle Oil
may be used for extended drain intervals of up to twice the manufacturer's suggested interval, while Screamin'
Eagle® is recommended for standard drain intervals. AMSOIL customers realize additional savings.
Harley-Davidson® claims Screamin' Eagle® Synthetic Motorcycle Oil has been "exclusively designed" for use in
their motorcycles, pointing to extensive bench testing and over 230,000 miles of durability testing to back it up.
AMSOIL INC. has 30 years of experience providing superior lubricating protection for all brands of motorcycles, and
AMSOIL Synthetic Motorcycle Oils have been tested in millions of over-the-road miles. Testimonials from countless
motorcyclists further demonstrate the superiority of AMSOIL Synthetic Motorcycle Oils.
Formulated with top-of-the-line synthetic base stocks and high-temperature deposit control additives, AMSOIL
Synthetic Motorcycle Oils provide superior protection and performance for motorcycles in all operating conditions.
AMSOIL Motorcycle Oils effectively withstand oxidation and thermal degradation, keep wear to an absolute minimum,
hold contaminants in suspension and keep engines running cool and clean.
AMSOIL Synthetic Motorcycle
Reduce operating temperatures.
Keep engines clean and deposit-free.
Provide maximum protection against wear.
Formulated without friction modifiers for smooth performance.
Saves money with extended drain intervals up to two times the manufacturers' recommendations.
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