This category is split into two distinct viscosities: There is a traditional high temperature/high shear viscosity (HTHS) and a lower HTHS viscosity, the latter targeted to achieve enhanced fuel economy.
CK-4 oils have traditional HTHS viscosity. They provide performance benefits exceeding CJ-4 engine oils, including improved oxidation resistance, shear stability and aeration control to enhance engine performance and durability, while still retaining backward compatibility to satisfy older makes and models. CK-4 oils are available in 5W-30 (coming soon), 5W-40, 10W-30 and 15W-40 viscosity grades, and are suitable for older on-highway engines.
FA-4 oils have lower HTHS viscosity. In addition to meeting the category performance requirements, including improved oxidation resistance, shear stability and aeration control, FA-4 oils are designed to provide enhanced fuel economy, but they are only available in 10W-30 viscosity grade.
Compared to their CK-4 counterparts, FA-4 oils have more limited backward compatibility. Each engine OEM will define the backward compatibility of FA-4 oils for their product line. Consequently, fleets that have engines that fall within the backward compatibility standard set by the OEM can use FA-4 oils across their entire fleet. See our OEM heavy-duty equipment chart
for PC-11 product recommendations.