The subject matter disclosed herein relates to a system and method for monitoring and controlling a combustion engine. In one embodiment, a system includes a controller configured to control operations of a combustion engine, to receive a signal from at least one knock sensor coupled to the combustion engine, to determine a knock margin value from the signal, and to estimate a fuel quality value of a fuel injected into the combustion engine based at least on a comparison between the knock margin value and a laboratory performance data set.