Duragard Diamond Plate Synthetic Blend CK-4 SAE 15W-40 Engine Oil is an extreme performance (HTHS) high-temperature, high-shear viscosity synthetic blend oil formulated to meet the significantly improved specifications for 2017 and newer engines while being fully compatible for 2016 and prior engines that previously used API CJ-4. API CK-4 will deliver more oxidization protection for hotter, heavy-duty engines, minimizing acid formation, deposits and viscosity increase, promoting reduced wear, improved shear stability, greater oxidation stability, and foam prevention.Duragard Diamond Plate Synthetic Blend CK-4 SAE 15W-40 Engine Oil is a new formula that is specifically engineered for use in mixed fleets, gasoline and diesel. CK-4 has a select additive package for exceptional performance at high temperatures and heavy loads with improved engine protection over previous CJ-4 formulas. The advance in oil technology standards establishes an oil quality specification that helps protect today and tomorrow diesel engines.Duragard Diamond Plate Synthetic Blend CK-4 SAE 15W-40 Engine Oil is a direct replacement for CJ-4 using the same viscosity grades in Synthetic or Synthetic Blend oil types providing protection for all future engine designs, while improving protection of current and previous engines. CK-4 and CJ-4 can be mixed and should have no detrimental impact to engines. However, it is recommended to completely change over to CK-4 oil by using a hot drain of the CJ-4 oil to help minimize residual oil and achieve full benefits of the new oil. Fleets using CJ-4 should implement a secondary storage for CK-4 or completely empty a CJ-4 tank before filling with Duragard Diamond Plate SAE 15W-40 API CK-4 Engine oil.
