Understanding Low-Speed Pre-Ignition (LSPI)
Efficiency is key to top engine performance, as new engines are being built to address fuel economy and emissions standards. To achieve efficiency and increased power, automakers began downsizing engines. Although efficiency was achieved, the performance of engines began to suffer. To offset the changes, automakers added turbochargers to the downsized engines to boost operating pressure. The reduction of engine size and the addition of turbochargers has led to the phenomenon of Low-Speed Pre-Ignition (LSPI). LSPI is “an abnormal combustion event caused by higher in-cylinder pressures…while operating under low speed, high-torque conditions“.
In modern engines, LSPI can occur because fuel droplets are released into the combustion chamber before the pistons are in the correct position. The premature release of fuel droplets can lead to a spark that destroys your pistons and connecting rods. Damage can range from broken spark plugs and cracked pistons to the extreme result of explosive engine failure.
2 Ways to Help prevent LSPI
- Check to make sure you are using oils that combat abnormal combustion. The American Petroleum Institute (API) introduced the adoption of SN PLUS which is a “proposed supplemental standard to the API SN specification, which will introduce oils for LSPI mitigation“. Prior to the announcement of API SN PLUS, Chevron exceeded SN PLUS requirements. As a reflection of the changes by API, Chevron has upgraded all Havoline and Supreme PCMO lines and beginning mid-October will begin distributing changes to packaging styles on a rolling basis.
- Look through your vehicle’s owner manual to decipher the manufacturer’s recommendation for fuel, based on the type of engine that you have.
To start giving your engine the protection against LSPI that it needs Contact us by visiting www.BrewerHendley.com .