A ceramic filter for trapping and combusting diesel exhaust particulates composed of an end-plugged cordierite honeycomb structure exhibiting a pore size distribution as determined by mercury porosimetry in which the quantity d.sub.50/(d.sub.50+d.sub.90) as related to pore size distribution is less than 0.70, a soot loaded permeability factor S.sub.f, as defined by the equation [d.sub.50/(d.sub.50+d.sub.90)]/[% porosity/100], of less than 1.55, and, a coefficient of thermal expansion (25 800.degree. C.) of no greater than 17.times.10.sup.-7/.degree. C. The ceramic filter further exhibits a median pore diameter, d.sub.50, of at least 4 micrometers and up to 40 micrometers. A method of making the filter is provided.