Recent equipment changes made by the engine builders in the CI-4 development process have advanced the need for the next level of API engine oil quality.

A license-able CI-4 Plus supplemental category is being developed to address the recent OEM specific requirements (Caterpillar ECF-1, Mack EO-N Premium Plus ‘03, and Cummins 20078 minimum TBN). It will serve to define better soot-viscosity control, piston deposit and cleanliness control as well as improved shear stability compared to current CI-4 oils.

The new supplemental category is expected to include the Mack T-11 engine test at EO-N Premium Plus ‘03 limits, extend the Kurt-Orban injector shear tests to 90 cycles and possibly require a minimum TBN.

Caterpillar still wants lower ash products, and is pushing for ECF-2 to include a multi-cylinder CAT engine. They have initiated work with their C13 diesel engines.

The earliest release date for the new Supplemental Category is October 1, 2004. The Caterpillar multi-cylinder engine test in the C13 engine may cause delays.