AMSOIL Signature series motor oils provide 90% better protection over other motor oils and have 50% more additives to fight sludge build-up. Engine sludge forms and can wreak havoc on engines… this article tells how to prevent it! This article will show the effects of sludge-how synthetic oil and additives prevent sludge. And how severe service on an engine invites sludge build-up. AMSOIL beats the competition in all tests for fighting sludge!