A model for calculating the trap pressure drop, particulate mass inside the trap and various particulate and trap properties was developed using the steady-state data and the theory developed by Konstandopoulos & Johnson, 1989. Changes were made with respect to the calculation of clean pressure drop, particulate layer porosity and the particulate layer permeability. This model was validated with the data obtained from the steady-state data run with different traps supplied by Corning Inc. The data were collected using the 1988 Cummins L-10 heavy-duty diesel engine using No.2 low sulfur diesel fuel. The three different traps were EX 80 (100 cell density), EX 80 (200 cell density) and EX 66 (100 cell density) all with a 229 mm diameter and 305 mm length. These traps were subjected to different particulate matter loadings at different speeds. The traps were not catalyzed. Subsequent loadings were performed without baking the trap in between to validate the pressure drop model with a certain amount of particulate mass already present in the trap. The pressure drop performance of the three traps were different from each other as they had different properties. The initial building up of particulate mass inside the EX 66 was different from other traps, because it had a larger pore size when compared to the EX 80. The model was able to predict this behavior by allowing a certain amount of particulate mass into the wall during the initial hours of loading followed by the building up of a particulate layer thereby increasing the pressure drop.Regeneration experiments were also performed with all the traps to determine the regeneration efficiency of these traps at different loading conditions. Filtration efficiency of the traps was determined experimentally by measuring the raw exhaust solid particulate matter concentration upstream and downstream of the trap.