Whether you daily drive a stock STI or rallycross a modified WRX, an efficient cooling system is key to extending the life of your flat-four. The plastic end tanks of the stock radiator are especially prone to cracking from years of constant variation in temperature. A radiator failure can result in overheating, head gasket failure, and other engine damage that can quickly put an end to a fun day at the track. Protect your investment with the Mishimoto Performance Radiator, engineered specifically for the 2001-2007 Subaru WRX and STI. After identifying the radiator in these vehicles as a weak point, our engineers set out to provide an efficient, durable radiator that can take the abuse of competitive driving and provide the reliability you need for daily commuting. -- The Mishimoto Subaru radiator features all-aluminum construction, which provides increased heat and pressure tolerance, improved heat dissipation, and improved cooling efficiency. The 100% brazed aluminum core and TIG-welded end tanks provide optimal durability and years of efficient and reliable service. This radiator is a complete bolt-in unit that replaces the factory radiator without requiring any modification to your Subaru. The Mishimoto Subaru Performance Aluminum Radiator includes a high-pressure 1.3 bar radiator cap. This cap effectively raises the boiling point of the coolant, thus providing a higher threshold for safe temperatures and resulting in a more efficient cooling system. Additionally, a second radiator cap is included for use on the expansion tank. This radiator provides a significant increase in coolant capacity, which allows for aggressive driving while retaining safe coolant temperatures. Keep your Subaru on the street and out of the shop with the Mishimoto Subaru WRX and STI Performance Aluminum Radiator. As with all our products, this radiator includes the Mishimoto Lifetime Warranty.