Methods and systems are provided for optimal operation of a gasoline particulate filter coupled to an engine exhaust system. Based on engine operating conditions, a target soot level on the GPF may be determined, and one or more engine operating parameters may be adjusted to maintain the actual GPF soot level at the target level. In one example, if the actual GPF soot level is lower than the target level, one or more of a fuel injection timing and a fuel rail pressure may be adjusted to increase soot generation, and if the actual GPF soot level is higher than the target level, the GPF may be regenerated until the actual soot level reaches the target level.