Mobil Delvac PC-11 with mechanic changing oil

Understanding API CK-4 and FA-4

What are CK-4 and FA-4 oils all about? Which diesel engine oil should I use? And how will using these heavy-duty diesel engine oils affect my fleet maintenance? If you still have questions about Mobil CK-4 and FA-4 oils, then you’ve come to the right place. Learn everything you need to know about the latest diesel engine oils here.
  • Improved performance with Mobil Delvac™ heavy-duty diesel engine oils

    The gold standard in engine oil

    Get the best tech for big trucks. Discover how API CK-4 and FA-4 Mobil Delvac™ heavy-duty diesel engine oils outperform CJ-4 oils.

  • mobil delvac ck 4 fa 4 engine oil

    API CK-4 or FA-4

    Find out which oil is right for your trucks. See our OEM heavy-duty equipment chart for CK-4 and FA-4 product recommendations.

  • new oil formulation

    The development of API CK-4 and FA-4

    Get more of the story behind CK-4 and FA-4 oils. Plus, learn how your fleet can make the switch to these advanced oils.