Abstract: The invention provides a fuel treatment system for cracking hydrocarbons in fuel for combustion engines. The system comprises a primary ducting component having an exhaust gas inlet zone, and a secondary ducting component which includes a fuel enrichment component and a processing chamber. The processing chamber may have an outlet zone connectable to the combustion engine. The inlet zone of the primary ducting component and the outlet zone of the processing chamber may be configured in a heat exchange relationship with each other and in a counter-current gas flow direction with respect to each other. During operation of the system, heat from hottest volumes of the exhaust gas flowing in a furthest upstream portion of the ducting arrangement may be transferred to fuel-enriched exhaust gas flowing in a furthest downstream portion of the processing chamber.