BMW Auxiliary Coolant Reservoir Cap Color:Black supporting up to 550 WHP

supporting up to 550 WHP (rated for 475 WHP on 100% E85)

Fuel economy unaffected during light throttle cruising

High-Flow Washable Air Filter: Reusable design for consistent airflow and efficiency

Fuel economy during normal driving is unchanged and it's compatible with all driving modes including towing

BMW Auxiliary Coolant Reservoir Cap Color:Black supporting up to 550 WHPThe Precision Raceworks Auxiliary Coolant Reservoir Cap is a functional and stunningly stylish way to add a nice touch to any engine bay! This cap come in three color options so there is always a color that will work for you! Black with Billet, Black with Blue, and the Stealth series (all black). Many people don't realize it but the OEM caps have a pressure release valve built into them. Often times aftermarket companies don't know this either or just