The Best Oil for a Harley

Published May 25, 2024, by Joseph Feghali

AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil is a high-performance lubricant that is designed for those who demand the very best synthetic oil protection. It has been developed from comprehensive research and is specifically designed to excel in all areas unique to motorcycles, such as the high temperatures of air-cooled engines like Harley-Davidson* V-twins, wet-clutch lubrication, extreme-pressure areas of gears and chains, and rust common to short trips and storage. Synthetic V-Twin Oil is multi-functional and satisfies the lubrication requirements of both domestic and foreign motorcycles.

Big, powerful V-twin engines run extremely hot, especially in summer during stop-and-go traffic. High heat breaks down oil formulated for standard service, inviting wear, and performance-robbing deposits. AMSOIL Synthetic V-Twin Motorcycle Oil is formulated with naturally heat-resistant synthetic base oils that resist oxidation in extreme heat. It contains a heavy treatment of anti-wear additives to reduce wear regardless of operating conditions. Following 1,000 miles of dyno testing where oil temperature averaged 367°F and cylinder head temperature averaged 465°F, AMSOIL V-Twin Oil fought piston-ring deposits that cause sticking and piston scuffing, preserving maximum compression and power (see image).

Harley Davidson 20w-50 synthetic oil

AMSOIL V-Twin Oil provides excellent protection in both transmissions and primary chaincases. It is shear stable and resists thinning from mechanical activity. AMSOIL V-Twin Motorcycle Oil performs like a gear lube without the negative effects of extreme-pressure additives. It resists viscosity breakdown 8X better than Harley-Davidson SYN3* for improved protection against compensator and transmission gear wear.

After 1,000 miles (1,609 km) of extreme-heat dyno testing, AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil protected against piston-ring sticking and piston scuffing for maximum compression and power.

AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil contains no friction modifiers and promotes smooth shifting and positive clutch engagement. It controls heat and helps prevent slippage and glazing, while its high total base number (TBN) helps improve clutch life by resisting the acids that can degrade clutch material

Best Synthetic Oil for Rust Protection

Motorcycles can be prone to rust from storage, humidity and short drives. Rust has the potential to cause major damage such as roller-bearing failure, wear, compression loss, and blow-by. Good rust protection, however, comes by design and is not natural to motor oils. Unlike many motorcycle oils, AMSOIL Synthetic V-Twin Oil contains special anti-rust agents. It passes the ASTM D1748 humidity cabinet rust test, demonstrating superior rust protection to help your engine achieve maximum performance and long life.