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 nearly 80 percent larger than that left by AMSOIL Synthetic 20W-50 Motorcycle Oil. Article Continued
Article: Harley Rider: Amsoil fulfills its Claims