As part of an ongoing investigation into the effects of compressor fouling on gas turbine performance, the stage stacking technique was used in conjunction with generalized turbine characteristics to simulate the performance of two common pipeline engines, the G. E. LM2500 and the Solar Centaur. A linear fouling model was introduced that simulates the progressive buildup of contaminants in the compressor by modifying the appropriate stage flow and efficiency characteristics in a stepwise fashion. This simulation of the onset and progressive nature of compressor fouling allows quantitative analysis of performance deterioration to be performed on the basis of trends noted in monitored parameters. A preliminary study into how severely a given level of fouling will affect engines of different size indicated that stage loading may be the more critical parameter.