Low-speed pre-ignition (LSPI) is a symptom of today’s power-dense engines. Automakers are aggressively downsizing engines to meet strict fuel-economy and emissions standards – while also improving power and torque output. They’ve achieved those seemingly opposing goals through gasoline direct-inject (GDI) engines, often coupled with a turbocharger. Although favorable to performance, these technologies heighten the possibility of LSPI events, which can destroy pistons and connecting rods. A properly formulated motor oil is critical for protecting your engine against LSPI. So, what is the best motor oil for LSPI?
What Is Low-Speed Pre-Ignition (LSPI)?
Low-speed pre-ignition (LSPI), also known as “stochastic pre-ignition” (SPI) or simply “super knock,” is the spontaneous ignition of the fuel/air mixture prior to spark-triggered ignition that can cause pressure spikes, loud knocking noises and catastrophic damage.
LSPI events are infrequent and random, most commonly occurring when the engine is under high load at low RPM, such as rapidly accelerating from a stoplight. But LSPI is more damaging than “engine knock” of the past. In some cases, a single event is sufficient to cause catastrophic engine damage.
Vehicle manufacturers like GM* and Ford* have addressed LSPI by designing tests to determine a motor oil’s ability to prevent it. The GM SPI test records the number of peak pressure events during high-load operation in a turbocharged engine. Passing the test is required to meet the GM dexos1® Gen 2 specification.
Engine: GM 2.0L EcoTec,* LHU
Duration: Five hours
Measures: Number of peak pressure pre-ignition events
Simulates: Turbocharged vehicle operating in high torque and at low speed
Requirement: At least three of the five total tests with zero peak pressure LSPI
events and no tests with more than two peak pressure events
Other LSPI Specifications
API SN PLUS and API SP are additional specifications requested by the automobile industry to protect passenger vehicles from LSPI. In addition, ILSAC GF-6 requires an LSPI test that uses a Ford engine. The current formulations of AMSOIL Signature Series, XL and OE Synthetic Motor Oils all meet or exceed these specifications.
What Is The Best Motor Oil For LSPI?
You can be confident in AMSOIL synthetic motor oils to protect your vehicle against LSPI. AMSOIL Signature Series, XL and OE Synthetic Motor Oils achieved 100% protection against LSPI – providing you with 100% peace of mind.
Signature Series Synthetic Motor Oil achieved 100% protection against LSPI.1 Zero occurrences of LSPI were recorded throughout five consecutive tests.
XL Synthetic Motor Oil features unique chemistry proven to protect your engine against the harmful effects of low-speed pre-ignition (LSPI). XL achieved 100% protection against LSPI.2 Zero occurrences of LSPI were recorded throughout five consecutive tests.
OE Synthetic Motor Oil achieved 100% protection against LSPI3 in the engine test required by the GM dexos1 Gen 2 specification. Zero occurrences of LSPI were recorded throughout five consecutive tests.
To learn more about LSPI and how AMSOIL synthetic motor oils protect modern engines, go here.
1Based on zero LSPI events in five consecutive tests of AMSOIL Signature Series 5W-30 motor oil in the LSPI engine test required by the GM dexos1® Gen 2 specification.
2Based on zero LSPI events in five consecutive tests of AMSOIL XL 5W-30 motor oil in the LSPI engine test required by the GM dexos1® Gen 2 specification.
3Based on zero LSPI events in five consecutive tests of AMSOIL OE 5W-30 motor oil in the LSPI engine test required by the GM dexos1® Gen 2 specification.