Next Level Performance
August 25, 2026 • 10 min read
Our Verdict
The Mishimoto Performance Intercooler Kit is the best all-around upgrade for the 2016-2018 Focus RS, pairing a bar-and-plate core with a full silicone piping kit.
It adds 36% more core volume and drops charge-air outlet temperatures by nearly 40% to eliminate heat soak. Focus ST 2.0T owners get the same benefit from the matching Mishimoto ST kit, while COBB’s V2 core is the pick if you need a 50-state CARB-legal part.
Shop Our Top Pick →A front-mount intercooler is the single most cost-effective way to fight heat soak on the turbocharged Ford Focus ST and RS. The factory 2.0L and 2.3L EcoBoost engines make strong numbers on paper, but their small, dense OEM intercoolers heat-soak after just a few hard pulls — the ECU pulls timing, boost tapers, and your quarter-mile times fall off as the charge-air temperature climbs. Upgrading to a larger bar-and-plate core restores consistent power on back-to-back runs. In this guide the team at NLP Performance in Tampa, FL compares the five best Ford Focus ST and RS intercooler upgrades we stock, with real core specs, dyno-backed gains, CARB compliance notes, and pricing to help you pick the right one.
Why the Ford Focus ST and RS Need an Intercooler Upgrade
The stock Focus ST and RS intercoolers heat-soak because they are too small to dissipate the charge-air heat these EcoBoost engines generate under sustained boost. The 2013-2018 Focus ST runs a 2.0L EcoBoost (roughly 252 horsepower) and the 2016-2018 Focus RS runs a 2.3L EcoBoost (350 horsepower), yet both leave the factory with compact, tube-and-fin coolers optimized for packaging, not repeated wide-open-throttle runs. On a hot Tampa afternoon or a second dyno pull, intake temperatures spike, the ECU pulls ignition timing to protect the engine, and measurable power disappears.
A larger bar-and-plate intercooler adds internal volume and external fin area so the core sheds heat faster and resists heat soak. Mishimoto measured a nearly 40% reduction in air-outlet temperature on the Focus RS core, plus verified gains of 7 horsepower and 8 lb-ft at the wheels — and, more importantly, those numbers stay consistent pull after pull. For tuned cars running a Stage 1 or Stage 2 calibration, a bigger intercooler is a prerequisite, not an option: it lets the tune hold timing and deliver the power it promises.
Bar-and-plate cores add internal volume and fin area to fight heat soak.
How We Ranked the Best Focus Intercoolers
We ranked these intercoolers on four factors that matter to Focus ST and RS owners: core construction and cooling capacity, whether a complete piping kit is included, CARB/emissions compliance, and value for the money. Bar-and-plate cores earn priority over tube-and-fin designs because they move more air and resist heat soak better. Kits that bundle mandrel-bent hard pipes and wire-reinforced silicone couplers score higher than bare cores, since the restrictive factory hot-side pipe and turbo muffler are a real bottleneck. Every part below is in stock and ships from NLP Performance.
The 5 Best Ford Focus ST and RS Intercoolers
1. Mishimoto Focus RS Performance Intercooler Kit — Best Overall (RS)
The Mishimoto Performance Intercooler Kit for the 2016-2018 Focus RS is our top pick because it upgrades the core and the piping in one box. The bar-and-plate core carries 36% more volume and a 214% larger external fin surface area than stock, reducing air-outlet temperature by almost 40% while adding 7 horsepower and 8 lb-ft. The included hot-side pipe has 40% more internal volume and is shaped to route air over the factory PTU cooler, and the cold-side pipe uses five-layer wire-reinforced silicone. It carries Mishimoto’s lifetime warranty.
What We Like
- + Complete kit: core plus hot- and cold-side piping
- + 36% more core volume, nearly 40% lower outlet temps
- + Verified +7 HP / +8 lb-ft and consistent repeat pulls
- + Backed by Mishimoto’s lifetime warranty
Things to Consider
- – Not legal for sale/use in California (CARB)
- – Premium price versus a core-only upgrade
2. Mishimoto Focus ST Intercooler Kit — Best for the 2.0T ST
Focus ST owners get the same heat-soak fix with the Mishimoto 2013-2018 Focus ST Performance Intercooler Kit. Its bar-and-plate core opens up air channels the restrictive OEM core chokes off, and the kit deletes the factory turbo muffler in favor of a mandrel-bent aluminum hot-side pipe that flows 26% better. All told, Mishimoto measured a 21% increase in flow to and from the intercooler, with wire-reinforced silicone couplers replacing the failure-prone factory rubber. This silver-core, black-pipe version is the clean sleeper look.
What We Like
- + Deletes the restrictive OEM turbo muffler
- + 21% more flow, bar-and-plate core
- + Wire-reinforced silicone couplers for longevity
- + Direct fit with lifetime warranty
Things to Consider
- – Not CARB-compliant for California
- – Color/pipe combos affect price
The ST kit deletes the turbo muffler and adds a 26%-better-flowing hot-side pipe.
3. COBB Focus ST V2 Front Mount Intercooler — Best CARB-Legal Option
If you live in California or another CARB state, the COBB Focus ST V2 Front Mount Intercooler is the one to buy: it carries CARB Executive Order D-660-5, making it 50-state emissions legal. The V2 bar-and-plate core is engineered to pair with COBB’s Accessport tuning and Stage packages, so it is the natural choice for owners already inside the COBB ecosystem who want a compliant, proven upgrade path.
4. Injen Focus RS Bar-and-Plate FMIC — Best Value for the RS
The Injen FM9003i is a strong value for Focus RS owners who want a big bar-and-plate front-mount without the full piping kit price. It is precision TIG-welded with a brushed-aluminum silver finish, installs in about an hour, and is covered by Injen’s lifetime warranty. At just over $950 it undercuts the complete kits while still delivering the larger core that stops heat soak.
The TIG-welded Injen FM9003i installs in about an hour on the Focus RS.
5. Mishimoto Focus RS Intercooler (Core Only) — Best Budget Upgrade
Already have upgraded piping, or want the biggest cooling gain for the least money? The Mishimoto Focus RS Intercooler (I/C only) is the same bar-and-plate core as the full kit, minus the pipes, for around $860. It bolts to the factory or aftermarket piping and delivers the core-side cooling improvement that matters most, still under Mishimoto’s lifetime warranty.
Key Specifications — Mishimoto Focus RS Kit
Focus ST and RS Intercooler Comparison
| Kit | Platform | Core / Type | CARB-Legal | Price |
|---|---|---|---|---|
| Mishimoto RS Performance KitTop Pick | Focus RS 2.3T | Bar-and-plate + piping | No (CARB) | $1,299.95 |
| Mishimoto ST Intercooler Kit | Focus ST 2.0T | Bar-and-plate + piping | No (CARB) | $1,166.95 |
| COBB ST V2 FMIC | Focus ST 2.0T | Bar-and-plate | Yes (EO D-660-5) | $1,290.00 |
| Injen RS FMIC (FM9003i) | Focus RS 2.3T | Bar-and-plate | No (CARB) | $953.31 |
| Mishimoto RS Core Only | Focus RS 2.3T | Bar-and-plate core | No (CARB) | $859.95 |
Focus ST vs RS: Which Intercooler Do You Need?
Buy the intercooler that matches your engine: the 2.0L EcoBoost Focus ST and the 2.3L EcoBoost Focus RS use different-sized cores and piping, and they are not interchangeable. Choose a Focus ST kit (Mishimoto ST or COBB ST V2) for the 2013-2018 ST, and a Focus RS kit (Mishimoto RS or Injen FM9003i) for the 2016-2018 RS. If you are chasing a Stage 2 tune and big power, the complete Mishimoto kits with upgraded piping give the most headroom. If budget is the priority, the Injen RS FMIC or the Mishimoto RS core-only deliver most of the cooling benefit for less. And if you must stay 50-state emissions legal, the COBB ST V2 with its CARB EO is the clear answer.
Not sure which trim or year you have? The 2.3L RS was sold in the U.S. only for 2016-2018, while the 2.0L ST ran 2013-2018. All of these parts are direct-fit, but double-check your model year against each product’s fitment table before ordering, and browse our full intercooler collection or the broader cooling upgrades if you want to compare more options.
The core-only Focus RS intercooler pairs with factory or aftermarket piping.
Installation and What Else You Will Need
Most Focus ST and RS intercoolers are a direct, no-cut bolt-on that a competent DIYer can install in one to three hours with basic hand tools. The front bumper cover comes off to access the intercooler, then the OEM core and, on full kits, the hot- and cold-side pipes swap over to the new hardware. The Injen FM9003i is rated at about a one-hour install. Plan on removing the bumper, transferring any sensors, and re-checking clamp torque after a heat cycle. Pair the intercooler with a quality tune (COBB Accessport or similar) to take full advantage of the cooler charge-air temperatures — the hardware sets the ceiling, and the tune realizes it. A catch can and upgraded charge pipes are common companion upgrades on higher-horsepower builds.
Frequently Asked Questions
Does an intercooler upgrade add horsepower on the Focus ST or RS?
Yes, but modestly on a stock tune — Mishimoto measured about 7 horsepower and 8 lb-ft on the Focus RS. The bigger benefit is consistency: a larger bar-and-plate core stops heat soak, so the car holds timing and makes the same power on back-to-back pulls instead of falling off. On a Stage 1 or Stage 2 tune the gains are larger because the ECU can keep more timing in.
Are Ford Focus intercoolers CARB legal in California?
It depends on the brand. The COBB Focus ST V2 intercooler carries CARB Executive Order D-660-5 and is 50-state legal. The Mishimoto and Injen intercoolers listed here are not CARB-compliant and cannot be shipped to California addresses, so California buyers should choose the COBB unit.
Do I need a tune with a new intercooler?
No, an intercooler is safe to run on a stock ECU and will still reduce charge-air temperatures and heat soak. However, pairing it with a COBB Accessport or similar tune is where you unlock the biggest power gains, because the tune can hold more ignition timing once intake temperatures drop.
Will a Focus ST intercooler fit a Focus RS?
No. The 2.0L EcoBoost Focus ST (2013-2018) and 2.3L EcoBoost Focus RS (2016-2018) use different core sizes and piping routing, so intercoolers are engine-specific. Always match the part to your exact engine and model year using the product fitment table.
How long does it take to install a Focus intercooler?
Most Focus ST and RS intercoolers install in one to three hours as a direct bolt-on with no cutting. The front bumper cover must be removed for access. Injen rates its FM9003i Focus RS intercooler at roughly a one-hour install for an experienced installer.
Is a bar-and-plate intercooler better than tube-and-fin?
Bar-and-plate cores generally hold more internal volume and resist heat soak better, which is why every intercooler in this guide uses a bar-and-plate design. Tube-and-fin cores can cool slightly faster at light load and weigh less, but for a boosted Focus making repeated hard pulls, the bar-and-plate core is the more reliable choice.
Ready to Kill Heat Soak on Your Focus?
Shop bar-and-plate intercoolers for the Focus ST and RS, plus thousands more performance parts at NLP Performance.
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