Mishimoto MMRT-WRX-01E Aluminum Expansion Tank for 2002-2007 WRX/2004-2016 STI

Vehicle Fitment

• 2002-2007 Subaru WRX (GD/GG, 2.0 L EJ205/j EJ255); 2004-2016 Subaru WRX STI (GD GG 04-07; GE 08-14; VA 15-16, 2.5 L EJ257/EJ207); RWD/AWD

Features

• Direct-fit aluminum replacement for OEM plastic expansion tank
• TIG-welded 100% aluminum construction - no cracks or swelling
• Barbed fittings ensure leak-free OEM hose compatibility
• 50 % greater coolant capacity than stock tank
• Polished or matte-anodized finish - engine bay styling upgrade
• Matching design for Mishimoto aluminum radiator lineups
• Backed by Mishimoto Lifetime Warranty
• OEM radiator cap compatibility retained

Specifications

• Material: 6061 aluminum, TIG-welded
• Height: 98 mm (3.85 in); Width: 159 mm (6.25 in)
• Fluid capacity: ~776 cc (+50 % over OEM stock)
• Finish options: polished aluminum or matte-black anodized
• Includes barbed fittings for OE hose routing
• Weight: approx. 2 lb

Included Components

• 1x MMRT-WRX-01E aluminum expansion tank
• Barbed hose fittings pre-installed
• Mounting hardware (rubber bushings, bracket)
• Installation instructions

Product Description

The Mishimoto MMRT-WRX-01E aluminum expansion tank is designed as a direct OEM replacement for the stock plastic reservoir in Subaru WRX (2002-2007) and STI (2004-2016) models. Cracking and deformation of plastic tanks under thermal stress are common failure points; this robust 6061 aluminum replacement delivers long-lasting durability and improved under-hood aesthetics.

With TIG-welded construction and a 50 % boost in coolant capacity (~776 cc), this tank enhances cooling efficiency - especially under high heat from track, rally, or performance driving. It supports both polished and anodized finishes, and integrates seamlessly with Mishimoto radiator setups using existing hoses and radiator cap. Fitment is confirmed through trusted dealers Summit Racing, Rallysport Direct, and Mishimoto's official docs - covers EJ205, EJ255, EJ257, EJ207 engines. **Does not fit JDM twin-scroll STI versions**, so please verify your model code before ordering.