The Making of a New Category of Engine Oils:

The Environmental Protection Agency (EPA) is the driving force behind changes to diesel engine oil specifications. EPA regulations, which require reductions in exhaust gas emissions, has forced the majority of OEMs to redesign engines to meet more stringent emissions standards. These engine redesigns typically put additional stresses on the lubricant.
API CI-4 began as Proposed Category 9 (PC-9) and has been in development for several years. It is a distinguishable performance upgrade over API CH-4.

2 Reasons for the new CI-4 category:
1. The EPA mandated a 50 percent reduction of nitrogen oxide, or NOx, emissions below 1998 limits for diesel engines.
2. Engine design modifications to achieve a 50 percent reduction in emissions called for higher cylinder pressures, increased piston ring zone temperatures and, in most cases, Exhaust Gas Recirculation (EGR).


Impact of the Change
Lubricant Manufacturers have 9 months
Due to complications with EGR technology and agreement on test limits, lubricant manufacturers will have only nine months between test limit agreement (December 5, 2001) and licensing for API CI-4 oils (August 2002).

Backward Compatibility
From the beginning, API CI-4 was intended to be a category that is ?backward compatible.? Backward compatibility means API CI-4 oils will provide protection for both existing engines and new EGR engines coming to market in October 2002. To compensate for EGR, lubricant manufacturers have had to significantly boost their additive packages. Engine manufacturers were concerned that the additional chemistry would attack more sensitive older engine components and decrease engine life.