The work described in this paper aims to assist in the development of an exhaust gas fuel reformer for the enhancement of diesel particulate filter (DPF) aftertreatment performance. This was achieved by introducing H-2 and CO at various mixture ratios at a concentration of 6% (v/v) to a standardised DPF regeneration process in order to identify an optimised mixture ratio. In addition to this, emission measurements were performed pre and post filter to identify the impact of the additional mixtures on various emission components. A mixture ratio of 60% H-2 balanced with CO was identified as the optimised mixture ratio. This was due to this configuration demonstrating one of the most proficient regeneration profiles at a relatively low mean filter temperature of approximately 630 degrees C. Further to this, it was also noted that the addition of H-2 or H-2 and CO to the regeneration process resulted in an increase in NOx post filter while total hydrocarbons were reduced. Furthermore, the H-2/CO mixture addition resulted in an increase in CO2 post filter, the levels of which were proportional to the volume of CO contained within the introduced mixture. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.