Keep Your Engine Cleaner AMSOIL Signature Series has 50% more detergents² to help keep oil passages clean and promote oil circulation. It provides 90% better protection against sludge³ to keep your engine clean and long-lasting.
	Maximum Fuel Economy AMSOIL synthetic motor oils are formulated using molecularly uniform synthetic base oils that slip easily over one another and remain fluid in cold temperatures. They help reduce energy lost to friction and maximize fuel economy.
Change Your Oil Less Often With AMSOIL synthetic lubricants, you put more than industry-leading oil in your vehicle – you put time back into your schedule. Our extended-drain lubricants let you safely go longer between oil changes if you want, saving time spent on maintenance.
	Enthusiasts Love AMSOIL "I only use AMSOIL for my vehicles. 13 years and 250,000 miles later, still running smooth. Thank you." Scott, Verified Buyer
Why AMSOIL? We design our synthetic lubricants to exceed the toughest automaker and industry-performance standards so enthusiasts like you can maximize the performance and life of the vehicles.

AMSOIL vs. Harley-Davidson Oil: How We Perform

We submitted AMSOIL synthetic motorcycle oil and Harley-Davidson SYN3 oil to independent testing. Who came out on top?