Friction

[Fauxchemist2009]

Can an oil be dual rated Ck4,SN Sn+ and not be Energy Conserving? If not is there really even a difference anymore between the two other than HTHS?

 

[bullwinkle]

To be both CK-4 & SN, an oil is generally either Xw40 or a high HTHS Euro oil. I can't remember anything that was SN+ & CK-4 together, dual rated fleet oils seem to be getting less common except high $ Euro synthetic oils. IIRC API "Energy Conserving" has to be Xw30 or less, they discontinued that label after SM, SN & later are now "Resource Conserving".

 

[Fauxchemist2009]

To be both CK-4 & SN, an oil is generally either Xw40 or a high HTHS Euro oil. I can't remember anything that was SN+ & CK-4 together, dual rated fleet oils seem to be getting less common except high $ Euro synthetic oils. IIRC API "Energy Conserving" has to be Xw30 or less, they discontinued that label after SM, SN & later are now "Resource Conserving".

So in theory would it be fiscally irresponsible for a blender to give Xw-40 a "shot" of friction modifier same as they would say Xw-20,Xw-30

 

[ZeeOSix]

So in theory would it be fiscally irresponsible for a blender to give Xw-40 a "shot" of friction modifier same as they would say Xw-20,Xw-30

I'd think any good modern oil regardless of viscosity would have some AF/AW additives to reduce friction and wear since many engine components run in the boundry and mixed lubrication realms where metal-to-metal contact can occur.