Caterpillar Oil Aeration Test accepted into PC-11 category

The New Category Development Team (NCDT) for the upcoming heavy-duty diesel engine oil category being developed in North America dubbed “PC-11” has accepted a test into the category. The Caterpillar Oil Aeration Test (COAT) was unanimously voted in on 26 March via teleconference. The test is based on the Caterpillar C13 engine.

Before the vote, Hind Abi-Akar of Caterpillar gave an update on the test. The test parameters have been defined: figures for percentage average aeration as well as a procedure for density measurement have been specified. It was decided that no shutdowns are allowed during the last 20 hours of the 50-hour-long test, and that aeration levels would be measured from 40 to 50 hours of the test. She also shared that the Test Monitoring Center (TMC) is working on sourcing the six reference oils, and that the task force has defined the stand calibration and referencing process, and that all stands have satisfied the calibration requirements.

Elisa Santos of Infineum reviewed the statistical Matrix Data Update. Since the last meeting of the NCDT, analysis from recent tests at one of the labs, Lab A, showed that since the beginning of testing, there had been a restriction in an external oil circuit, altering pressure and therefore the aeration measurement. This invalidated most of the tests from this lab. At a different lab, it was found that the test parameters were not tightly controlled, invalidating about half that lab’s tests.

Going forward, Abi-Akar clarified that an adjustment structure is in place: “an unusual drop in [the pressure of an external oil line] will require investigation and correction,” and quality indices will be set up for all the pertinent operational parameters.

“Tests that are outside these parameters will be flagged,” she said.

Upon a re-evaluation of data from all the matrix tests, the task force decided to choose a subset of tests to represent current and future operation, meaning that a smaller set of data will be used to represent the test.

During the teleconference, Mike Ragomo of ExxonMobil commented that while ExxonMobil will support this decision, it does not want a precedent to be set for how small a data set can be after the matrix is run. Abi-Akar said this is a valid concern, but that the task force could probably not have foreseen this particular problem. Going forward, Santos said that the adjustment structure will be in place. The lab tests which were not chosen to represent the test will be marked as invalid.

Jim McGeehan of Chevron commented that the test procedure should specify silicone-free gaskets, as this element is not left for people to control. Abi-Akar responded that these gaskets are not yet available, but that a contingency plan is in place if a rebuild happens before they are available.

Dan Arcy of Shell, chairman of the NCDT, remarked that these comments should be included in the Test Development Final Report. Following this, a motion was passed to accept the Cat Aeration Test into the PC-11 category. All 12 members, which represented oil companies, additive companies and engine manufacturers, voted to accept the test.