A homogeneous-charge, compression-ignition engine (10) having engine coolant, an intake manifold and an exhaust manifold including a controller for advancing and retarding auto-ignition in the combustion chamber of the engine, the intake manifold providing a premixed combustible charge of air and fuel, the intake manifold having dual intake portions (26,28), one portion supplying unheated gas, and the other providing gas heated by engine coolant or exhaust gas, or both. A flow distributor valve (42) in the intake manifold gas flow passages (18,22,26) varies the intake temperature, thereby controlling auto-ignition timing and the combustion rate in the engine combustion chamber during the portion of the combustion cycle in which a homogeneous-charge, compression-ignition event occurs. The engine (10) includes a spark ignition system for initiating combustion when the engine load, for a given speed, increases to a defined level and when the engine speed for a given load increases to a defined level.
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