ASTM D4742 Test Method for Oxidation Stability of Gasoline Automotive Engine Oils
ASTM D4742 Standard Test Method for Oxidation Stability of Gasoline Automotive Engine Oils by Thin-Film Oxygen Uptake (TFOUT)
1. Scope
1.1 This test method evaluates the oxidation stability of engine oils for gasoline automotive engines. This test, run at 160°C, utilizes a high pressure reactor pressurized with oxygen along with a metal catalyst package, a fuel catalyst, and water in a partial simulation of the conditions to which an oil may be subjected in a gasoline combustion engine. This test method can be used for engine oils with viscosity in the range from 4 cSt (mm2/s) to 21 cSt (mm2/s) at 100°C, including re-refined oils.
1.2 This test method is not a substitute for the engine testing of an engine oil in established engine tests, such as Sequence IIID.
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.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.
2. Referenced Documents
2.1 ASTM Standards:
A 314 Specification for Stainless Steel Billets and Bars for Forging
B 211 Specification for Aluminum and Aluminum-Alloy Bar, Rod, and Wire
D664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D1193 Specification for Reagent Water
D2272 Test Method for Oxidation Stability of Steam-Turbine Oil by Rotating Bomb
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
E 1 Specification for ASTM Thermometers
E 144 Practice for Safe Use of Oxygen Combustion Bombs
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 break point - the precise point of time at which rapid oxidation of the oil begins.
3.1.2 oxidation induction time - the time until the oil begins to oxidize at a relatively rapid rate as indicated by the decrease of oxygen pressure.
3.1.3 oxygen uptake - oxygen absorbed by oil as a result of oil oxidation.
