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.

    Learn more
  • 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 about Energy efficiency guide: Saving energy on the road