Variable Inertia Charge System (Protege & Protege5)
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Variable Inertia Charge System (VICS) shutter valves in the intake manifold control length of intake air path, depending upon engine RPM. With engine speed less than 4750 RPM, the shutter valves close, improving torque output. At more than 4750 RPM, the shutter valves open, increasing airflow and improving high RPM performance.