2015-2021 Subaru WRX Intercoolers: Mishimoto vs Garrett

Upgrading the intercooler on a 2015-2021 Subaru WRX is one of the smartest bolt-ons you can make to the 268-horsepower FA20DIT, because the factory top-mount unit heat-soaks fast under repeated wide-open-throttle pulls. When intake air temperatures (IATs) climb, the ECU pulls ignition timing and boost to protect the engine, and your power fades pull after pull. A larger bar-and-plate intercooler restores dense, cool charge air so the little 2.0-liter turbo delivers consistent power on the street, the strip, and the track. Below, we compare the best WRX intercooler upgrades we stock in our Tampa, FL shop — Mishimoto versus Garrett versus aFe — with real specs, fitment, and pricing.

Why Does the FA20DIT WRX Need an Intercooler Upgrade?

The 2015-2021 WRX needs an intercooler upgrade because its compact factory top-mount intercooler (TMIC) is undersized for sustained boost and soaks up heat quickly. The FA20DIT 2.0L direct-injection turbo four makes 268 hp and 258 lb-ft from the factory, and it routes charge air through a small tube-and-fin core tucked under the hood scoop. That core works fine for a single pull, but on back-to-back pulls, autocross runs, or a hot Florida track day, the aluminum saturates with heat — a phenomenon called heat soak.

Once the core is heat-soaked, intake air temperatures spike well above ambient. The FA20DIT's ECU responds by trimming timing and dropping boost target, so the car feels flat and inconsistent. An upgraded bar-and-plate intercooler has far more internal surface area and thermal mass, so it rejects heat faster and recovers between pulls. The payoff is not just a bigger peak number — it is repeatable, reliable power and lower knock risk every time you get on the throttle.

Top-Mount vs Front-Mount: What Fits the VA WRX?

The 2015-2021 WRX (VA chassis) uses a factory top-mount intercooler fed by the hood scoop, so an upgraded top-mount is the simplest true bolt-on. A larger TMIC like the Mishimoto or Garrett units drops into the factory location, keeps the ram-air hood scoop working, and clears the OEM bypass valve with no cutting. That makes it the go-to choice for daily-driven and lightly modified cars that want quick heat-soak relief without fabrication.

A front-mount intercooler (FMIC) moves the core to the nose of the car for maximum airflow and capacity, which matters on high-horsepower E85 or big-turbo builds. The trade-off is custom charge-pipe routing, possible bumper trimming, and losing the tidy factory hood-scoop feed. For the vast majority of stock-turbo and Stage 1-to-Stage 2 WRX owners, an upgraded top-mount plus a mandrel-bent charge pipe delivers most of the benefit with none of the headache — which is exactly the combination we compare here.

The Best 2015-2021 WRX Intercoolers Compared

Here is how the three intercoolers and the supporting charge pipe stack up. All four are direct bolt-ons for the 2015-2021 Subaru WRX FA20DIT, and prices run roughly the $300 to $1,200 range depending on whether you want a complete kit, a bare performance core, or a value replacement.

Mishimoto Top-Mount Intercooler Kit: The Complete Bolt-On (Top Pick)

The Mishimoto Top-Mount Intercooler Kit is our top pick because it is a complete, engineered system — not just a core. It combines a cast-aluminum-end-tank, TIG-welded bar-and-plate intercooler with a matched set of mandrel-bent charge pipes and 5-ply silicone couplers, so you upgrade the core and the plumbing in one box. It bolts to the factory top-mount location, retains the OEM hood scoop, and clears the stock bypass valve. Mishimoto engineered it specifically for the 2015-plus WRX FA20DIT, and it also fits the 2014-2018 Forester 2.0XT.

Garrett FA20F Intercooler: Rated to 530 HP for Big Builds

The Garrett air-to-air intercooler is the pick when your WRX build is headed toward serious power. Garrett rates this bar-and-plate core to support up to 530 horsepower — roughly double the FA20DIT's factory 268 hp — making it the highest-flowing option here for high-boost, E85, or upgraded-turbo cars. It carries Garrett's motorsport-derived core design and fits the 2015-plus WRX FA20F 2.0L. Note that it ships as a performance core; it is CARB-restricted and cannot ship to California.

Mishimoto Street Performance TMIC: The Value Pick

The Mishimoto Street Performance Top-Mount Intercooler is the best value here at around $666, because it delivers a genuine bar-and-plate core upgrade while reusing the factory charge piping. It replaces the stock top-mount unit directly, so it is aimed at 2015-2021 WRX owners running a stock turbo who want to kill heat soak on the commute and the occasional canyon run without buying full plumbing. You get the same core-material advantage as the flagship kit, at a lower entry price.

aFe BladeRunner Charge Pipe: The Supporting Upgrade

The aFe BladeRunner hot-side charge pipe is the supporting mod that finishes the job, replacing the restrictive OEM plastic tube with 2.5-inch mandrel-bent aluminum. Smooth mandrel bends cut turbulence and pressure loss between the turbo and intercooler, and the kit ships with a CNC-machined turbo adapter flange, stainless T-bolt clamps, and heavy-duty 5-ply silicone couplers. It is the natural pairing for the Garrett core or the Mishimoto Street Performance intercooler, which reuse factory piping.

How Much Horsepower Does a WRX Intercooler Add?

On a stock tune, an intercooler by itself adds only a few peak horsepower — its real job is to recover the 10 to 20-plus horsepower that heat soak steals during back-to-back pulls, and to keep that power consistent. The FA20DIT's ECU is aggressive about pulling timing when intake air temps rise, so a cooler, denser charge lets the engine hold its tune. On a warm day or a track session, that is the difference between a strong first pull and a flat fifth pull.

The bigger gains come when the intercooler is part of a package. Add a cold-air intake, a downpipe or high-flow catted exhaust, and a Stage 1 or Stage 2 tune, and the cooler charge air lets a calibrator safely target more boost. That is where a bar-and-plate core earns its keep — and why the Garrett unit's 530 HP rating matters for owners planning an upgraded turbo or E85 down the road.

Do You Need a Tune and a Charge Pipe?

A direct-replacement intercooler does not strictly require a tune, but a supporting tune is strongly recommended to get the most from the upgrade — especially once you add boost or bolt-ons. The larger core changes charge-air volume slightly, and a proper Stage 1 or Stage 2 calibration lets the ECU take advantage of the cooler, denser air. If you are staying stock-turbo and simply want to end heat soak, even the value Mishimoto core is a worthwhile change on its own.

A hot-side charge pipe like the aFe BladeRunner is the ideal companion when you choose the Garrett core or the Mishimoto Street Performance intercooler, since those reuse the factory plumbing. Swapping the OEM plastic tube for mandrel-bent aluminum reduces the risk of a blown coupler under boost and trims pressure loss. If you buy the full Mishimoto Top-Mount Intercooler Kit, the charge pipes are already included — one of the reasons it earns our top pick. Not sure which combination fits your build? Our Tampa, FL team can match parts to your goals.