The application relates to spark initiation under varied aircharge density and composition. An engine is disclosed comprising at least two cylinders with spark plugs therein; an integrated exhaust manifold, the integrated exhaust manifold having a wall portion and an adjustable shutoff element within the wall portion wherein the wall portion divides exhaust pipes of the at least two cylinders and the adjustable shutoff element allows exhaust gas from a first cylinder into an exhaust pipe of an adjacent cylinder. Hot exhaust gas may be taken into an adjacent cylinder serving as ignition gas and allowing the engine of the present disclosure to undergo spark ignition at low loads, or autoignition at high loads.