Originally Posted By: Garak
In that case, I don't think OEMs will have to backspec. Assuming viscosity is correct and CK-4 is certified as backwards compatible by API, that's the end of it. The vast, vast majority of manuals call for a certain API spec or newer, not one spec only, and those cases that do are dodgy at best. Further, assuming the CK-4 lubes have the builder approvals, there's not much else necessary.
That is generally true. But once a owner gets their hands on the Lubrication and Fuels manuals from the OEM, it gets a little more complicated. The OEM's, unlike the personal vehicle sector, get into several significant details on what they allow and don't allow. The CJ-4 thing is just the starting point. After that, they list other conditions the oil must meet to qualify. And they are extremely detailed on max wear numbers, oil consumption issues, limits of TBN depletionetc. This is why I always get a copy on the OEM lube manual.
In that case, I don't think OEMs will have to backspec. Assuming viscosity is correct and CK-4 is certified as backwards compatible by API, that's the end of it. The vast, vast majority of manuals call for a certain API spec or newer, not one spec only, and those cases that do are dodgy at best. Further, assuming the CK-4 lubes have the builder approvals, there's not much else necessary.
That is generally true. But once a owner gets their hands on the Lubrication and Fuels manuals from the OEM, it gets a little more complicated. The OEM's, unlike the personal vehicle sector, get into several significant details on what they allow and don't allow. The CJ-4 thing is just the starting point. After that, they list other conditions the oil must meet to qualify. And they are extremely detailed on max wear numbers, oil consumption issues, limits of TBN depletionetc. This is why I always get a copy on the OEM lube manual.
