Significance and Use
5.1 This test method evaluates the ability of an automotive engine to mitigate preignition in the combustion chambers in turbocharged, direct injection, gasoline engines under low-speed and high-load operating conditions.
5.2 Varying quality reference oils, with known preignition tendencies, were used in developing the operating conditions of the test procedure.
5.3 The test method has applicability in gasoline-engine-oil specifications 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 ILSAC GF-6.
5.3.3 SAE Classification J183.
Scope
1.1 This laboratory engine test evaluates the ability of an automotive engine to mitigate preignition in the combustion chambers in gasoline, turbocharged, direct-injection (GTDI) engines under low-speed and high-load operating conditions. This test method is commonly known as the Ford low-speed, preignition (LSPI) test.
1.1.1 In vehicles, equipped with relatively small GTDI spark-ignition engines, preignition has occasionally occurred when the vehicles are operated under low-speed and high-load conditions. Uncontrolled, preignition may cause destructive engine damage.
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—Where there is no direct SI equivalent such as screw threads, national pipe threads/diameters, tubing size, wire gauge, or specified single source equipment.
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.
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.
