API CI-4 PLUS

API's service category for compression-ignition engines. Current category.

Name
Diesel engine oil, API CI-4 PLUS performance level
Category
Engine oil performance
Status
Current
Verified
30 August 2026

Products covered by this standard

Shell

4 products
Shell Engine oils

Mobil

8 products
Mobil Engine oils

Caterpillar

2 products
Caterpillar Engine oils
  • CAT DEO ULS 10W-30

    API CK-4 heavy-duty diesel engine oil for engines with aftertreatment, backward compatible

    • Heavy-duty diesel

    SAE 10W-30

  • CAT DEO-ULS 15W-40

    API CK-4 heavy-duty diesel engine oil for engines with aftertreatment, backward compatible

    • Heavy-duty diesel

    SAE 15W-40

API standards

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