API CG-4 Class

Section API classes for diesel engines, article 3 of 12188 words, 2 minutes

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

The class was introduced in 1995. Engine oils of this class are recommended for four-stroke diesel engines in buses, trucks and tractor units of both highway and off-highway type, operating under heavy loads as well as high-speed regimes. API CG-4 engine oil suits engines that run on high-quality fuel with a sulphur content of no more than 0.05%, as well as engines with no special fuel-quality requirements (where sulphur content can reach 0.5%).

Oils certified to the API CG-4 class must more effectively prevent wear of internal engine parts, formation of deposits on internal surfaces and pistons, oxidation, foaming, and soot build-up (properties especially needed by modern highway buses and tractor-unit engines).

The API CG-4 class was created in response to new US environmental and exhaust-toxicity requirements and standards (1994 revision). Engine oils of this class can be used in engines for which the API CD, API CE, or API CF-4 classes are recommended. The main drawback limiting widespread use of oils in this class, for example in Eastern Europe and Asia, is the strong dependence of the oil's service life on the quality of the fuel used.