A series of tests were run to evaluate a newly developed, open-celled ceramic filtering media for trapping diesel particulate soot in heavy duty diesel engine exhaust streams. The porous ceramic material is unique in that it contains as part of its structure an integral ceramic membrane that increases the trapping efficiency of the ceramic foam as well as controlling soot “blow-off” at high exhaust velocities. Data are presented showing the increase in both trapping efficiency and backpressure as soot is collected during successive EPA heavy duty transient tests. The majority of the tests were performed at the Southwest Research Institute in San Antonio, Texas using a Caterpillar 3406B, 400 HP diesel engine. Additional data are also presented in a number of over-the-road durability trials on a 8300 Series International Tractor powered by a 315 HP Cummins engine.