Harley Davidson Synthetic Oil


All these years Harley Davidson had been telling their customers not to use a synthetic oil (because they did not have one of their own!), yet now they have one with their name on the bottle, however when you look at the test data it performs very poorly compared to the AMSOIL 20W-50 Synthetic Motorcycle Oil and allows for a wear scar of over 50% greater than AMSOIL. Here's the article:

Why Harley Owners Choose AMSOIL
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 Oils is best for the unique requirements of Harley-Davidson air-cooled V-twin engines. However, laboratory testing has consistently revealed the 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.

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 hear 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 Harley's.  

The laboratory test results for ASTM D4172 Four-Ball Wear Test show the AMSOIL 20W-50 Synthetic Motorcycle Oil leaves a wear scar of 0.39 mm. The Harley Davidson Screamin' Eagle 20W-50 Synthetic Motorcycle Oil leaves a wear scar of 0.70 mm.  That's over 50% larger than AMSOIL. The bottom line is that AMSOIL will protect your engine from wear better than the Screamin' Eagle Synthetic will.

The fact is, engine oil in Harley-Davidson motorcycle 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 lubrication qualities of the oil and increase 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 contaminates allowing motorcyclist to safely extend drain intervals.

In support of their about-face and the introduction of synthetic oil, Harley maintains, the Motor Company has never supported the use of synthetic products in our vehicles because there has never been any test validation completed on the numerous formulation 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 H/D Buell motorcycles.

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 form, or makes it better than, many other synthetic motorcycle oil formulation. 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 and oil that can be used in the engines, primary chain cases and transmission 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-50W Synthetic Motorcycle Oil may also be used in the engines. Primary chaincases and transmission of these applications, providing superior lubrication protection in each component.

How does Screamin Eagle Synthetic Motorcycle Oil measure up to AMSOIL in wear protection?  Four-Ball Wear 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 that AMSOIL 20W-50 Synthetic motorcycle Oil.

Not only does AMSOIL Synthetic Motorcycle Oil offers 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, 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 lubrication 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 Motorcycles Oils.

Formulated with top-of-the-line synthetic base stocks and high-temperature deposits 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 Oils

ˇReduce operating temperatures
ˇKeep engines clean and deposit-free
ˇProvides maximum protection against wear
ˇFormulated without friction modifiers for smooth performance
ˇSaves money with extended drain intervals of up to two times the manufacturers recommendation