Honeycomb based diesel particulate filters have proven to be extremely effective in the removal of diesel soot. Under certain conditions, involving heavy soot loads and a shift of the engine into the idle mode during the early stages of the regeneration process, the current designs of cordierite filters have shown some tendency toward partial melting.A brief review of the SAE literature is presented, indicating that the temperatures reached during regeneration decrease substantially as the bulk heat capacity of the filter increases. Analysis of these literature data indicates that the top temperatures experienced during regeneration can be decreased by hundreds of degrees, by relatively modest increases in the bulk heat capacity of the bodies.New data are presented confirming how the top temperature varies with different filter designs in which the bulk heat capacity varies. Data are presented for cordierite filters and for new oxide materials of different designs that are currently under development.The length/diameter ratio can also play a substantial role in the top temperatures seen during regeneration. Data are presented showing how a minor reduction in part length can lead to substantial reduction in the top temperatures for a given soot load.Data are presented which indicate that reducing the length/diameter ratio leads to a reduction in pressure drop for both clean and soot laden filters.