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“.