A method for predicting engine performance, the method comprising: receiving a fluid sample from a first engine , the fluid sample having particles suspended therein; extracting a plurality of particles from the fluid sample; obtaining features of the plurality of particles extracted from the fluid sample and obtaining the features of particles of reference fluid samples from a plurality of reference engines, the features comprising chemical composition and one or more physical characteristics of each particle; determining, using size and aspect ratio as axes of a two-dimensional coordinate system, a plurality of average distances between particles in each of a first profile of particles and a reference profile of particles and a respective center of each of the first profile and the reference profile; determining, from the features, a plurality of correlation indices indicative of a level of correlation between the first engine and each one of the plurality of reference engines, wherein each correlation index is determined based on the plurality of average distances and represents a correlation between a distribution of particles in the fluid sample and a given one of the reference fluid samples; comparing the correlation indices to a threshold to determine a subset of the plurality of reference engines for which the threshold is exceeded; obtaining performance history for the engines in the subset; determining, from the performance history, that the first engine has a similarity in performance with the engines in the subset; and generating, based on the similarity in performance, an output indicating a predicted performance for the first engine . receiving a fluid sample from a first engine , the fluid sample having particles suspended therein; extracting a plurality of particles from the fluid sample; obtaining features of the plurality of particles extracted from the fluid sample and obtaining the features of particles of reference fluid samples from a plurality of reference engines, the features comprising chemical composition and one or more physical characteristics of each particle; determining, using size and aspect ratio as axes of a two-dimensional coordinate system, a plurality of average distances between particles in each of a first profile of particles and a reference profile of particles and a respective center of each of the first profile and the reference profile; determining, from the features, a plurality of correlation indices indicative of a level of correlation between the first engine and each one of the plurality of reference engines, wherein each correlation index is determined based on the plurality of average distances and represents a correlation between a distribution of particles in the fluid sample and a given one of the reference fluid samples; comparing the correlation indices to a threshold to determine a subset of the plurality of reference engines for which the threshold is exceeded; obtaining performance history for the engines in the subset; determining, from the performance history, that the first engine has a similarity in performance with the engines in the subset; and generating, based on the similarity in performance, an output indicating a predicted performance for the first engine . <EOS>