Compatible: (2.0L)

2015 – 2021 Subaru WRX

Your vehicle requires 2 bottles of full strength coolant or 3 bottles of premixed coolant

The Mishimoto 2015 Subaru WRX Performance Aluminum Radiator is designed and engineered to reduce coolant temperatures by +20F (+11C), maximize cooling efficiency by up to 15%, and most importantly to protect your car from overheating. It is the ideal upgrade to the stock 2015 WRX radiator, whether you drive your 2015 WRX daily or take it for track runs. The Mishimoto 2015 WRX radiator features a lightweight dual core, 100% brazed aluminum, and polished end tanks, enhancing the overall performance of your engine. The engineers at Mishimoto designed this 2015 WRX aluminum radiator with a 117% increase in coolant capacity, 42% increase in coolant surface area, and 34% increase in air surface area, making it an ideal upgrade to keep your new FA20-DIT running cool! Every Mishimoto aluminum radiator is a direct stock fit making installation effortless, with no cutting or modification required. This 2015 WRX radiator comes with a Mishimoto1.3 Bar High-Pressure Radiator Capand, like our entire line of 2015 WRX parts, this aluminum radiator comes with the unparalleled Mishimoto Lifetime Warranty.

• Direct fit for 2015+ Subaru WRX
• Reduces coolant temperatures by 20+F (11+C)
• 117% increase in coolant capacity
• 42% increase in coolant surface area (tubes)
• 34% increase in air surface area (fins)
• 15% more efficient than stock
• 100% brazed aluminum core
• TIG-welded to perfection
• IncludedHigh-Pressure 1.3 Bar Radiator Capraises the boiling point of engine coolant to provide a safer and more efficient system
• IncludesMagnetic Drain Plug
• Mishimoto Lifetime Warranty

PURCHASE INCLUDES

Mishimoto Radiator
Mishimoto Radiator Cap
Magnetic Drain Plug
(4) M6 x 1.0 x 16mm Flange Hex Bolts
Mishimoto Lifetime Warranty

VEHICLE SPECS

PRODUCT SPECS

MISHIMOTO 2015 SUBARU WRX PERFORMANCE ALUMINUM RADIATOR, PART 2: EVALUATION OF FIRST PROTOTYPE RADIATOR

Now that we had our first prototype unit in, it was time to evaluate fitment and determine if any changes were necessary when compared to the stock unit. First, we swapped the shrouds to see if any fitment issues existed because of the added size of the Mishimoto unit.

Mishimoto prototype 1 (right) fan shroud fitmentMishimoto prototype 1 (top) fan shroud fitment

Both the stock and Mishimoto plug-n-play aluminum fan shrouds fit perfectly with the mounting points on our prototype radiator. After verifying this fitment, we installed the prototype in the vehicle to ensure that all other fitment points were specd correctly.

Mishimoto prototype 1 installedMishimoto prototype 1 installedMishimoto prototype 1 installedMishimoto prototype 1 installed

The prototype unit fit quite nicely! We had some minor adjustments to make with a few end-tank features, but for the most part, mounting points were spot on. The core we designed for this prototype is 42 mm thick, more than two times the thickness of the stock unit. Core fin density in this prototype was similar to the stock unit. After a discussion with our team we determined that the core on our first prototype would need a few modifications. First, we would reduce the thickness of the core. The FA20DIT front-mounted turbocharger setup would likely present some potential fitment concerns. We decided to allow for future turbocharger and charge pipe upgrades by providing some additional clearance for upgraded components in this area. By decreasing the core thickness to 35 mm, our radiator would still be double the thickness of the stock unit and would provide a nice increase in fluid capacity.

A second modification to our prototype core will be in the fin and tube composition. Instead of simply matching the density of the stock unit, we would be improving upon it. Our radiator will utilize shorter fins, which allow for more overall rows and a greater surface area. A greater fin surface area provides more heat-transfer contact points, which then result in lower fluid temperatures. This core would be a two-row design, providing greater fluid capacity.

Once we had a plan for our second prototype, we set to work putting together the models and drawings. Check back next time for the introduction and evaluation of our second prototype unit!

Thanks!

MISHIMOTO 2015 SUBARU WRX PERFORMANCE ALUMINUM RADIATOR, PART 4: PROTOTYPE RADIATOR PERFORMANCE TESTING AND PROJECT COMPLETION

Now that we had a finalized prototype, it was time to test this component to ensure that our improvements over the stock unit resulted in real-world advantages for our customers. An aluminum radiator provides the instantaneous benefit of increased reliability over the stock plastic unit. Despite this, cooling performance is always our primary goal with a heat exchanger.

Prior to actual road testing, our engineering team put together a few charts illustrating the improvements over the stock radiator.

Comparison of coolant surface area in Mishimoto and stock radiators

Coolant surface area refers to the space occupied by the tubes in the radiator. The amount of coolant surface area affects both fluid capacity and overall heat transfer contact points. A larger coolant surface area results in greater heat transfer and lower temperature. The Mishimoto prototype features a 42% increase in coolant surface area compared to the stock radiator.

Comparison of air surface area in Mishimoto and stock radiators

The next improvement is seen in air surface area, represented by external fin surface area in the chart above. Airflow passes through the fins to transfer heat from the coolant tubes. Once again, a larger surface area will result in greater heat transfer. The Mishimoto prototype unit increases air surface area by 34% compared to the stock radiator.

With the additional thickness of the Mishimoto radiator and its dual-row core, the fluid capacity is increased significantly. The stock radiators fluid capacity is 0.39 gal, while the Mishimoto radiators fluid capacity is 0.84 gal. This amounts to a 117% increase in capacity of the Mishimoto radiator over stock.

Now to the road testing! First we installed our temperature sensors on the radiator hoses and prepared our data collection tools.

Mishimoto radiator with temperature sensors installed

Our test vehicle would be the Mishimoto 2015 WRX CVT-equipped shop vehicle. All data points were collected on the highway and compiled on the same day. The vehicle was driven at 60 mph cruising speeds for 5 minutes, for each particular setup. Special attention was given to the traffic in front of the WRX to ensure that a fresh stream of airflow was supplied to the radiator. We used 100% distilled water in the cooling system. Check out the temperature results below!

Comparison of radiator outlet temperatures in Mis