AFE 46-51003 BladeRunner GT Series Engine Coolant Expansion Tank for 11-24 300 / Challenger / Charger (3.6L V6 & 5.7L Hemi). The expansion tank offers a premium upgrade to the factory expansion tank in your car. Say Goodbye to the aging plastics of the stock tank, susceptible to yellowing and brittleness over time, affecting both appearance and reliability.