Subaru WRX/STi Overflow Tank 2008-2014

Interested in picking up our 2008-2014 WRX/STi overflow tank? Check out our discounted pre-sale linked below.

2008-2014 Subaru WRX aluminum overflow tank pre-sale!

We last left you with some details of our initial design and a hint of an upcoming pre-sale for this overflow tank. Unfortunately, since that initial test fit we hit a few snags in the design process. Our goal with this product is to provide compatible fitment with all our other 2008+ WRX and STi components. This required numerous stages of test fitting, one of which revealed an issue. With our larger 3-row X-Line aluminum radiator installed, our sight tube on this expansion tank design ended up too close to the belt drive system on our Subaru.

We decided a revision was necessary. Although the two components were not physically touching, the clearances were just too tight for our comfort. Luckily, our team had an alternate means of measuring fluid within the tank. This comes in the form of a dipstick!

Check out a few 3D models

Interested in picking up our 2008-2014 WRX/STi overflow tank? Check out our discounted pre-sale linked below.

2008-2014 Subaru WRX aluminum overflow tank pre-sale!

If you haven't noticed, the folks here at Mishimoto are not fans of plastic use for cooling system components. A large number of our products provide a more durable material, aluminum, to replace the failure-prone plastic parts, and now we are focusing on another line of products, our aluminum coolant expansion tanks. We offer two different options for the WRX/STI and one for the new Mustang EcoBoost. This article is focused around our newest addition, an aluminum overflow tank for the 2008+ WRX and STI.

Product Design

We won't be making any significant changes to the design of this tank compared to the stock unit, except for the construction material. Enlarging the tank's capacity will have no impact on fluid temperatures or cooling efficiency, so this will not be necessary.

We snagged a stock overflow tank and started gathering