Significance and Use
5.1 This test method was developed to evaluate automotive engine oils for protection against oil thickening and piston deposits during moderately high-speed, hightemperature service.
5.1.1 The increase in kinematic viscosity of the oil indicates the tendency of an oil to thicken because of oxidation. In automotive service, such thickening can cause oil pump starvation and resultant catastrophic engine failures.
5.1.2 The deposit ratings for an oil indicate the tendency for the formation of deposits throughout the engine, including those that can cause sticking of the piston rings in their grooves. In automotive service, such ring sticking can cause a loss of compression pressures in the engine.
5.2 The test method was developed to correlate with oils of known good and poor protection against oil thickening and piston deposits. Specially formulated oils that produce less than desirable results with unleaded fuels were also used during the development of this test.
5.3 The Sequence IIIH engine oil test has been recommended as a replacement for the Sequence IIIG test and is expected to be used in specifications and classifications of engine lubricating oils, such as the following:
5.3.1 Specification D4485.
5.3.2 Military Specification MIL-PRF-2104.
5.3.3 SAE Classification J183.
Scope
1.1 This test method covers an engine test procedure for evaluating automotive engine oils for certain high-temperature performance characteristics, including oil thickening (as measured by kinematic viscosity increase), piston deposits, ring sticking, oil consumption, and phosphorus retention. Such oils include both single-viscosity and multiviscosity grade oils that are used in both spark-ignition, gasoline-fueled engines, as well as in diesel engines.
1.1.1 Additionally, with nonmandatory supplemental requirements, a Sequence IIIHA Test (Mini Rotary Viscometer and Cold Cranking Simulator measurements), or a Sequence IIIHB Test (phosphorus retention measurement) can be conducted. These supplemental test procedures are contained in Appendix X1 and Appendix X2, respectively.
NOTE 1: Companion test methods used to evaluate engine oil performance for specification requirements are discussed in SAE J304.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.2.1 Exceptions:
1.2.1.1 Where there is no direct SI equivalent such as screw threads, national pipe threads/diameters, tubing sizes, and valve sizes and springs.
1.2.1.2 The ring end gaps in Table A8.7, the dimensions for the blowby ventilation support bracket in Fig. A3.2, and the torque wrenches in Table A8.1 are in inch-pound units.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific warning statements are provided in 6.11.6, 7.1, 7.2.1, and 7.3.
1.4 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.
