Four-bolt main bearing caps reduce noise and vibration. New intake ports aid volumetric efficiency and enhance fuel and air mixture distribution. A total of 18 bolts secure each head, encircling each cylinder with five bolts. A lighter aluminum intake manifold is cast using a lost-foam process for greater precision and reduced weight. Crankcase ventilation passages are cast integrally with the heads to eliminate the need for external valves and plumbing.
Fuel is delivered by a high-pressure sequential fuel injection system.
Air is metered by an electronic throttle control that needs no mechanical link between the accelerator pedal and the engine. Throttle operation is instead governed by the powertrain control module through an electric motor. Throttle response and the engine's reliability are improved while build complexity is reduced. Spark timing is keyed by a reluctor ring attached at the rear of the crankshaft. Improved water jacket design eliminates coolant flow restrictions.