ASTM D8279-22a

5.1?This test method evaluates an automotive engine oil's lubricating efficiency in inhibiting timing-chain lengthening under operating conditions selected to accelerate timing-chain wear. Varying quality reference oils of known wear performance were used in developing the operating conditions of the test procedure.

5.2?The test method can be used to screen lubricants for satisfactory lubrication of an engine timing chain and has application in gasoline, automotive, engine-oil specifications. It is expected to be used in specifications and classifications of engine lubricating oils, such as the following:

1.1?Undesirable timing-chain wear has been observed with gasoline, turbocharged, direct-injection (GTDI) engines in field service, and data from correlating laboratory engine tests have shown that chain wear can be affected by appropriately formulated engine lubricating. A laboratory engine test has been developed to provide a means for screening lubricating oils for that specific purpose. The laboratory engine test is 216 h in length, conducted under varying conditions, and the increase in timing-chain length determined at the end of test is the primary result. This test method is commonly known as the Sequence X, Chain Wear (CW) Test.

1.2?The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.3?Table of Contents:?

1.4?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.