Mishimoto Aluminum Expansion Tank, Red: Ford Focus ST 2013 - 2018, Focus RS 2016 - 2018

  • $245.95
  • Save $81

Add some reliability and engine bay styling to your Focus RS/ST with the Mishimoto RS/ST expansion tank. This tank features internal baffles to prevent coolant starvation from overflow ports on the engine. Also, during high speed cornering, braking, and acceleration, the internal baffles reduce coolant sloshing. The engineers at Mishimoto have included a sight tube to allow for proper observation of hot and cold coolant levels, making engine maintenance much easier.

Eventually, you’ll have to consider the health of your plastic expansion tank. Plastic is prone to failure after years of constant temperature variations. The Mishimoto tank is constructed from durable, TIG-welded aluminum for optimal durability and longevity. It reuses the stock expansion tank cap and includes an overflow nipple on the fill neck for adding an additional coolant tank so your Focus RS / ST stays NHRA legal. All areas of concern are covered with this upgrade.

It’s worth noting the Focus’s stock tank is an engine bay eye sore, whereas the Mishimoto tank comes in three different variants to help with aesthetic customization: black, wrinkle red, or Wrinkle Nitrous Blue. Each of these options works with both the 2013+ Focus ST and the new 2016+ Focus RS. For convenience, you can install your new coolant tank upgrade in under one hour as it was engineered with perfect fitment in mind. Like all our Focus RS parts, this expansion tank also includes the Mishimoto Lifetime Warranty.

Installation Instructions:

Installation Guide


  • Direct fit for the 2016+ Ford Focus RS / 2013+ Ford Focus ST
  • Sight tube allows for proper hot and cold coolant levels
  • Internal baffle keeps coolant near overflow port during aggressive driving, preventing air entry into coolant system
  • 100% aluminum, fully-welded construction for maximum durability during repeated temperature transitions
  • Overflow nipple on fill neck allows for installation of additional NHRA-mandated overflow reservoir
  • Fits with stock overflow tank cap
  • Available in Wrinkle Nitrous Blue, wrinkle red, or black powder-coated finish
  • Mishimoto Lifetime Warranty

Purchase Includes:

(1) Aluminum Expansion Tank w/ Sight Tube
(1) Overflow Hose
(2) Rubber Sleeves
Mishimoto Lifetime Warranty

Fits 2013+ Ford Focus ST
2016+ Ford Focus RS

Engine Codes 2.0L EcoBoost
2.3L EcoBoost

Material 6061 Aluminum

Note After a few hot and cold cycles, Mishimoto recommends checking the sight tube on the side of the expansion tank to confirm proper coolant level.

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