Starting this month, Shell Rotella T multigrade 15W-40 and 5W-40 heavy-duty engine oils will begin carrying the American Petroleum Institute's (API) new CI-4 Plus classification.
The “plus” grade requires passing two additional engine tests to demonstrate superior soot handling capability and shear stability control.
The CI-4 Plus classification was created by API to indicate better performance with cooled exhaust gas recirculation (EGR) systems used in current low-emission diesel engines.
Shell says its CI-4 version of Rotella T did not require any modifications to pass the two additional tests. Shell's Rimula Premium SAE 15W-40 and Pennzoil Long-Life SAE 15W-40 also meet the criteria for CI-4 Plus, according to the company.