We armed Signature Series with an advanced detergent system that protects against harmful deposits and low-speed pre-ignition (LSPI). Most new engines feature gasoline direct injection (GDI), often combined with a turbocharger to boost power and improve fuel economy. These new technologies, when combined with a poorly formulated motor oil, promote LSPI and threaten engine operation. LSPI is the spontaneous ignition of the fuel/air mixture prior to spark-triggered ignition. It occurs in today's advanced engines and is much more destructive than typical pre-ignition. A properly formulated motor oil is critical for protecting your engine.Original equipment manufacturers (OEMs) like GM* have addressed the issue by designing tests to determine a motor oil’s ability to prevent LSPI. Signature Series Synthetic Motor Oil achieved 100 percent protection against LSPI1 in the engine test required by the GM dexos1 Gen 2 specification - zero occurrences were recorded throughout five consecutive tests.