4.1 The test method is designed to predict the high temperature deposit forming tendencies of an engine oil subject to the added oxidizing stress of a turbocharger. This test method can be used to screen oil samples or as a quality assurance tool.

1.1 This test method covers the procedure to determine the amount of deposits formed by automotive engine oils utilizing the thermo-oxidation engine oil simulation test (TEOST2).3 An interlaboratory study (see Section 17) has determined it to be applicable over the range from 10 mg to 65 mg total deposits.

Note 1: Operational experience with the test method has shown the test method to be applicable to engine oils having deposits over the range from 2 mg to 180 mg total deposits.

1.2 The values stated in SI units are to be regarded as standard.

1.2.1 Milligrams (mg), grams (g), milliliters (mL), and liters are the units provided, because they are an industry accepted standard.

1.2.2 Exception—Pounds per square inch gauge (psig) is provided for information only in 6.2.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.