NOVELTY - An integrated fuel reformer-engine system includes on-board catalytic partial oxidation fuel reformer (12), exhaust catalyst (24), and controller. The fuel reformer converts liquid fuel and supply of air into hydrogen-rich reformate (18a, 18b). The controller adjusts the supply of air (16a) and/or combination of reformate and liquid fuel to the engine and adjusts the supply of reformate to the exhaust catalyst.    USE - For use in larger, higher emitting vehicles e.g. vehicles employing diesel engines.    ADVANTAGE - The inventive system is capable of robustly meeting super ultra low emission vehicle (SULEV) emissions criteria over the range of real-world operating conditions. It enables reduction of hydrogen and nitrogen oxide emissions to near zero at cold start through the periods of vehicle road loads. It reduces exhaust emissions while providing fuel economy and overall engine efficiency. It is capable of providing low emissions during off-cycle conditions and during failure modes of the exhaust after-treatment system.    DETAILED DESCRIPTION - An integrated fuel reformer-engine system (10) comprises on-board catalytic partial oxidation fuel reformer, engine (20), exhaust catalyst, and controller. The fuel reformer receives a supply of and converts the liquid fuel and supply of air into hydrogen-rich reformate. The engine has reformate intake, liquid fuel intake, air intake, and exhaust outlet. The exhaust catalyst has an intake for receiving the engine exhaust (22) and/or reformate, and an outlet for discharging the exhaust after treatment. The controller adjusts the supply of air and/or combination of reformate and the liquid fuel to the engine and for adjusting the supply of reformate to the exhaust catalyst to provide non-stoichiometric lean fueling of the engine and provide low hydrocarbon and nitrogen oxide (NOx) emissions over a range of operating conditions from cold-start through to high engine loads. The controller supplies reformate to the exhaust catalyst for a time sufficient to warm the exhaust catalyst to operational temperature.    An INDEPENDENT CLAIM is also included for operating an integrated fuel reformer-engine system comprising producing a hydrogen-rich reformate fuel with an on-board catalytic partial oxidation fuel reformer; fueling an engine using the reformate, and/or liquid fuel; treating engine exhaust and/or reformate in an exhaust catalyst; and controlling the supply to the engine and the exhaust catalyst of the reformate, the liquid fuel, and/or air to provide non-stoichiometric lean fueling of the engine and achieve low hydrocarbon and NOx emissions over a range of engine operating conditions from cold-start to high engine loads. The controlling comprises controlling the supply of the reformate, and/or the liquid fuel to the engine so as to supply the engine with 1OO% reformate fueling during starting, idling, and low engine load operating conditions and to supply the engine with a combination of the liquid fuel, the reformate, and recirculated exhaust gas fueling, as needed, during medium to high engine load conditions.    DESCRIPTION OF DRAWING(S) - The drawing shows a block schematic view of a reformer-based cold start system.    System (10)    Fuel reformer (12)    Air (16a)    Hydrogen-rich reformate (18a, 18b)    Engine (20)    Exhaust (22)    Catalyst (24)