API CI-4 (CI-4 PLUS) Class

Section API classes for diesel engines, article 1 of 12175 words, 1 minute

In this section: 12 articles
  1. API CI-4 (CI-4 PLUS) Class
  2. API CH-4 Class
  3. API CG-4 Class
  4. API CF-2 (CF-II) Class
  5. API CF-4 Class
  6. API CF Class
  7. API SE Class: Diesel Engines from 1983
  8. API CD-II Class
  9. API CD Class
  10. API CC Class
  11. API CB Class
  12. API SA Class: Diesel Engines

A new performance class of engine oils for diesel engines. Compared with API CI-4, the requirements for soot content as well as for volatility and high-temperature oxidation have been raised. To be certified in this classification, an engine oil must be tested in seventeen engine tests.

The class was introduced in 2002. These engine oils are used in modern diesel engines with various types of injection and forced induction.

An engine oil that meets this class must contain suitable detergent-dispersant additives and, compared with the CH-4 class, offers greater resistance to thermal oxidation as well as better dispersancy. In addition, such oils provide a substantial reduction in engine-oil consumption by lowering volatility and reducing evaporation at operating temperatures up to 370°C under the influence of gases. Requirements for cold pumpability have also been tightened, and the service life of engine clearances, tolerances and seals has been extended through improved oil flow.

The API CI-4 class was introduced in response to new, stricter environmental and exhaust-toxicity requirements applying to engines produced from October 1, 2002.