• 4min

Expert knowledge on low speed pre ignition (LSPI)


We explain how to avoid low speed pre ignition (LSPI) with LIQUI MOLY products.

Modern, high-performance engines with direct injection, suffer from an increased risk of premature ignition at low engine speeds. The term “low speed pre ignition” (LSPI) refers to the premature ignition phenomenon in the engine. It describes an undesired combustion before the planned ignition. The premature explosion in the combustion chamber counteracts the natural piston movement. This can lead to engine knocking and thus to serious, irreparable engine damage.

Give your customers what they need:°Our specially designed motor oils from the Special Tec AA range and the Special Tec DX1 have been developed to prevent LSPI. As of the API SN Plus+RC specification, these are subjected to an additional LSPI test.

Irreparable piston damage due to LSPI.
Increasing pressure in the combustion chamber through LSPI.

The Special Tec DX1 is a high-tech low-friction motor oil based on synthetic technology. It optimizes fuel consumption, ensures excellent cold-starting characteristics, optimum wear protection and excellent engine cleanliness. The innovative additive technology minimizes LSPI and thus ensures a longer engine service life. In addition, it is ideally suited for long oil change intervals and high engine requirements.

It was developed specifically for the requirements of GM and Opel vehicles with gasoline engines. To some extent, other vehicle manufacturers such as Chrysler, Ford, Kia, Honda, Hyundai, Mazda, Nissan, Toyota etc., have called for a lubricant with these specifications for different types of vehicles.

  • Outstanding engine cleanliness
  • Excellent wear protection
  • Ensures lower fuel consumption
  • Tested for use with turbochargers and catalytic converters
  • Reduction of low speed pre ignition (LSPI) or stochastic pre ignition (SPI)

The Special Tec AA motor oils are most suitable for modern Asian and American gasoline engines. They are particularly suited to long oil change intervals and high engine demands.

  • Reduction of low speed pre ignition (LSPI)
  • Extends the service life of the engine
  • Outstanding engine cleanliness
  • Optimum wear protection
  • Saves fuel and reduces pollutant emissions
  • Optimum aging stability

Our additive for preventing LSPI engine damage

Modern direct-injection turbocharged gasoline engines have a highly stressed injection system. The injection nozzles reach directly into the combustion chamber and are therefore exposed to high temperatures, pressures and the influence of combustion residues. Deposits form at the nozzle outlet openings within a short time, ensuring that the gasoline is no longer atomized so finely. This worsens the emission values and increases the fuel consumption. The deposits can begin to glow due to the high temperatures, which can then lead to engine knocking.

Deposits on injectors, pistons and combustion chamber are considered an essential factor for LSPI.

The Pro-Line Direct Injection Cleaner contains polyetheramine (PEA) as an active ingredient, which eliminates precisely these deposits. “Active PEA is a highly effective cleaning chemical that removes even stubborn deposits from injectors, pistons and combustion chambers,” explains David Kaiser, Head of Research and Development at LIQUI MOLY. “With regular use, it also provides permanent protection against new carbon deposits.”

The additive can be used during any engine check and is recommended by LIQUI MOLY as an alternative to Opel OEM part number 95 599 923 (Opel Technical Service Bulletin 3319). It is so effective that it only has to be added every 5,000 kilometers. It is also suitable for all cars with direct injection or intake manifold injection with a 4-stroke petrol engine. 

  • Outstanding engine cleanliness
  • Exceptional cleaning effect
  • Cleans the fuel system
  • Polyetheramine technology
  • Cleans combustion chamber and injectors