AMSOIL recently set about to find what impact their synthetic motorcycle oil and NGK Iridium spark plugs would have on the horsepower and torque delivery in late model V-Twin Harley-Davidson motorcycles. We were quite interested to see these results as we had always received stellar customer reviews of the motorcycle oil’s ability to deliver smooth power, improved shifting and cooler operation. AMSOIL submitted AMSOIL 20W-50 Synthetic Motorcycle Oil (MCV) and NGK Iridium IX Spark Plugs to Cycle Solutions Inc., one of the top motorcycle dyno tuners in the U.S. Tests were conducted on a 2006 Harley-Davidson Screamin Eagle 103 Ultra and a 2002 Harley-Davidson Screamin Eagle 103 Ultra. Conventional oil and spark plugs were used for the baseline. Tests were then conducted with just the synthetic 20W-50 alone, then the Iridium spark plugs alone and then both together. The results were impressive and it is easy to see where adding AMSOIL synthetic oil and NGK Iridium spark plugs can add very inexpensive horsepower and torque to your ride. Enjoy the AMSOIL Synthetic 20W-50 Motorcycle Oil/NGK Iridium IX Harley-Davidson Dyno Test.