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Mishimoto Oil Cooler Kit – 2015-2021 STI

Mishimoto Oil Cooler Kit – 2015-2021 STI


  • 20 F (16 C) temperature drop
  • Minimal pressure loss
  • Direct fit for the 2015+ STI
  • This oil cooler kit retains the use of your stock liquid to liquid oil cooler unit




The Subaru STI provides a great balance of power, handling, and reliability. As with any vehicle, controlling fluid temperatures will ensure consistent power and engine longevity. The Mishimoto Subaru STI Oil Cooler Kit was developed specifically for the 2015-2021 STI and is a great addition to any street or track-driven vehicle. A large Mishimoto 19-row cooler mounts in the front bumper to provide optimal airflow and cooling efficiency.

The included direct-fit mounting brackets and preassembled stainless steel lines with -10AN fittings will ensure an easy and hassle-free installation. This Mishimoto cooler is proven to reduce oil temperatures by 20+°F (16+°C) while maintaining minimal pressure loss. For further heat protection, this Mishimoto Subaru Oil Cooler Kit includes thermal reflective wrap for the oil lines, providing substantial heat deflection from the nearby exhaust.

The Mishimoto Subaru STI Oil Cooler Kit can be customized to meet your needs with either a Sleek Silver or Stealth Black cooler and your choice of the Mishimoto Oil Sandwich Plate or the Thermostatic Oil Sandwich Plate. As with all our products, this kit includes the Mishimoto Lifetime Warranty.

Quick Specs

  • Direct fit for the 2015-2021 Subaru STI
  • Proven 20+°F (16+°C) drop in oil temperature
  • Full bolt-on oil cooling solution for street and track vehicles
  • No modification necessary for installation
  • Billet aluminum thermostatic oil sandwich plate allows oil to reach optimum temperature
  • Includes preassembled stainless steel braided oil lines with -10AN fittings
  • Cooler available in Sleek Silver or Stealth Black
  • This oil cooler kit retains the use of your stock liquid to liquid oil cooler unit
  • Easily replaceable thermostat allows you to customize your fluid temperature
  • Additional thermostats available in 160°F, 185°F, and 200°F
  • Mishimoto Lifetime Warranty


  • Application-Specific Mounting Brackets
  • 19-Row Oil Cooler
  • 3.5-ft Stainless Steel Braided Hose with 150 -10AN Fittings
  • 4-ft Stainless Steel Braided Hose with 90 and 150 -10AN Fittings
  • M20 Sandwich Plate
  • M20 Stainless Steel Sandwich Plate Adapter
  • M20 x -10AN Straight Fittings
  • Mounting Hardware Set
  • Mishimoto Lifetime Warranty



Additional Information

Weight 11.2 lbs
Dimensions 18.6 × 15 × 8.4 in
Cooler Color & Thermostatic Options

Silver, Non Thermostatic, Black, Non Thermostatic, Silver, Thermostatic, Black Thermostatic


2015-2021 STI


Installation Notes

Torque Specs

Recommended torque specification for all straight fittings and banjo bolts: 15-25 ft/lbs (operating range). Do not exceed the maximum torque rating of 35 ft/lbs.

Please Note

It is the installer’s responsibility to check all thermostat plugs, NPT plugs, line fittings, and other connections to assure they are fully tightened before operating the vehicle. Mishimoto recommends that you check all connections at regular intervals, especially during the first few miles after installation.

Mishimoto fully inspects and cleans all products prior to packaging. However, it is recommended that customers flush the oil cooler with one quart of clean oil prior to installation to remove any debris accumulated during shipping.