Below you will find some general lubricant information and updates from trends in the industry.PC-11: New upcoming API Heavy Duty Specifications (CK-4 & FA-4)http://www.whatispc-11.com/API Categories: quick referencehttp://www.api.org/products-and-services/engine-oil/eolcs-categories-and-documents/oil-categories#tab_ilsacViscosity Chart: