Significance and Use
The test method is designed to predict the deposit-forming tendencies of engine oil in the piston ring belt and upper piston crown area. Correlation has been shown between the TEOST MHT procedure and the TU3MH Peugeot engine test in deposit formation. Such deposits formed in the ring-belt area of a reciprocating engine piston can cause problems with engine operation and longevity. It is one of the required test methods in Specification D 4485 to define API Category-Identified engine oils.
1.1 This test method covers the procedure to determine the mass of deposit formed on a specially constructed test rod exposed to repetitive passage of 8.5 g of engine oil over the rod in a thin film under oxidative and catalytic conditions at 285°C. The range of applicability of the Moderately High Temperature Thermo-Oxidation Engine Test (TEOST MHT ) test method as derived from an interlaboratory study is approximately 10 to 100 mg. However, experience indicates that deposit values from 1 to 150 mg or greater may be obtained.
1.2 This test method uses a patented instrument, method and patented, numbered, and registered depositor rods traceable to the manufacturer and made specifically for the practice and precision of the test method.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3.1 The values stated in SI units are to be regarded as standard. Although not an SI unit, the special name, litre (L) is allowed by SI for the cubic decimetre (dm3) and the millilitre (mL) for the SI cubic centimetre (cm3).
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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D4485 Specification for Performance of Active API Service Category Engine Oils
D6335 Test Method for Determination of High Temperature Deposits by Thermo-Oxidation Engine Oil Simulation Test
deposits; engine oil; oxidation; thermal decomposition; thermal oxidation; Engine (lubricating) oils; Piston deposits; TEOST (thermo-oxidation engine oil simulation test); Thermal decomposition; Thermal oxidation;
ICS Number Code 75.100 (Lubricants, industrial oils and related products)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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