When properly maintained, the Subaru flat - four is well known for its substantial power and impressive reliability. Proper regulation of coolant temperature is key to extending the life of your EJ - powered Subaru. Highly modified turbocharger setups and aggressive driving can result in high temperatures, which increases wear on internal engine components. Mishimoto's X - line radiator is engineered specifically for the 2001 - 2007 Subaru WRX and STI and features a large three - row core and full aluminum construction. This design yields optimal temperatures even in the most demanding environments. This radiator also features a 100 - percent brazed aluminum core with TIG - welded end tanks for increased durability, longevity, and a substantial increase in coolant capacity. The large three - row core enhances surface contact, resulting in improved efficiency, improved heat transfer, and lower engine coolant temperatures for your Subaru. The Mishimoto Subaru WRX and STI radiator includes a high - pressure 1.3 bar radiator cap, which effectively raises the boiling point of coolant to create a safer and more efficient system. Included with this radiator is a Mishimoto magnetic oil drain plug that removes metal fragments circulating in the coolant system, thus further protecting your engine. Whether you are looking for a reliable stock replacement radiator or a heat exchanger efficient enough for track abuse, the Mishimoto Subaru WRX and STI X - line Performance Aluminum Radiator is an ideal choice. As with all our products, this radiator is backed by the Mishimoto Lifetime Warranty.