1.1 该实验室发动机测试评估了汽车发动机在低速和高负荷运行条件下减轻汽油、涡轮增压直喷（GTDI）发动机燃烧室预燃的能力。这种测试方法通常被称为福特低速预点火（LSPI）测试。 1.1.1 在配备相对较小的GTDI火花点火式发动机的车辆中，当车辆在低速和高负载条件下运行时，偶尔会发生预燃。不受控制的提前点火可能会对发动机造成破坏性损坏。 1.2 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.2.1 例外情况-- 如果没有直接的SI等效物，如螺纹、国家管道螺纹/直径、管道尺寸、线规或指定的单一来源设备。 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 该试验方法评估了汽车发动机在低速和高负荷运行条件下减轻涡轮增压、直喷汽油发动机燃烧室中预燃的能力。 5.2 在开发试验程序的操作条件时，使用了具有已知预燃趋势的不同质量的参考油。 5.3 该试验方法适用于汽油- 发动机机油规格，预计将用于发动机润滑油的规格和分类，例如: 5.3.1 规格 D4485 . 5.3.2 ILSAC GF-6。 5.3.3 SAE分类J183。

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. ====== 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.