An air induction system is arranged to introduce air into a plurality of combustion chambers. The air induction system includes intake passages through which the air flows to the combustion chambers. Throttle valves are arranged to regulate an amount of the air flowing through the intake passages. Auxiliary runners communicate with the intake passages at a location positioned downstream of the throttle valves. The respective runners are unified with each other to form a common chamber. A single conduit has an end communicating with the common chamber and another end communicating with a location that generally is at atmospheric pressure. The air flowing through the conduit, the common chamber and the auxiliary runners also is supplied to the combustion chambers. The common chamber can be positioned next to the intake passages. A control valve can be provided at a location along the single conduit.