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 oil should I use? And how will using these oils affect my fleet? If you still have questions about 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 golds 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.

  • 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 API CK-4 and FA-4 oil icons

    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.

  • mac truck in desert

    Fleet performance

    Keep your trucks and your business going strong with the latest industry information, PC-11 oil recommendations and energy efficiency tips.

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  • a fleet of trucks moves down the highway fueled by Mobil Delvac products and solutions

    Energy efficiency guide: Saving energy on the road

    Use this helpful energy efficiency guide to make sure that your fleet and business save energy and money on and off the road.

    Learn more