The FA20 and FA24 are best compared as parts of two different BRZ and 86 generations rather than as isolated engines. The naturally aspirated FA20 powered the first-generation Subaru BRZ, Scion FR-S, and Toyota 86, while the naturally aspirated FA24 powers the second-generation BRZ and GR86 with greater displacement and stronger midrange output.
Both engines preserve the lightweight, rear-wheel-drive character that defines the platform, but they deliver it differently. The FA20 rewards momentum and engine speed. The FA24 provides more usable torque without abandoning naturally aspirated response. Choosing between them therefore involves the complete car, including purchase price, condition, electronics, cooling, oil control, brakes, tires, and intended use.
FA20 vs. FA24 at a Glance
| Category | FA20 | FA24 |
|---|---|---|
| Architecture | 2.0-liter aluminum flat-four | 2.4-liter aluminum flat-four |
| BRZ/86 induction | Naturally aspirated | Naturally aspirated FA24D, distinct from the turbo FA24F used in other Subaru platforms |
| Factory context | 2013–2020 BRZ, FR-S, and Toyota 86 | 2022+ BRZ and GR86 |
| Driving character | High-rpm, momentum-focused performance | Stronger midrange torque and easier acceleration |
| Main appeal | Lower-cost entry into the platform and mature aftermarket support | Better factory pace and more useful everyday torque |
| Main tradeoff | Pronounced midrange torque dip in stock form | Higher entry cost and generation-specific components |
FA20: The First-Generation Formula
The FA20 fits the original BRZ and 86 philosophy closely. It encourages the driver to preserve momentum, use the upper portion of the rev range, and rely on chassis balance rather than low-speed torque. That character can be rewarding on a back road, autocross course, or technical track where driver inputs matter more than straight-line acceleration.
The first-generation platform also offers a mature aftermarket. Exhaust, header, intake, suspension, brake, cooling, and calibration options are widely understood. That does not make every used FA20 car equally desirable, however. Oil level, maintenance history, previous track use, calibration history, accident repairs, and applicable recall work should all be investigated before purchase.
For a direct-fit first-generation airflow upgrade, the Mishimoto performance cold-air intake offers a purpose-built option for the FA20-powered BRZ and FR-S while retaining a clean engine-bay layout.
Mishimoto 13+ Subaru BRZ/Scion FR-S Performance Cold Air Intake Kit - Wrinkle Black
An FA20 car can also represent the more affordable route into the platform. The lower initial cost may leave more room in the budget for tires, brake service, suspension setup, maintenance, and driver education—all of which can have a greater effect on the complete driving experience than chasing engine output alone.
FA24: More Torque Without Losing the Formula
The FA24 addresses the FA20’s most noticeable everyday weakness: limited midrange torque. Its additional displacement gives the second-generation BRZ and GR86 stronger acceleration in normal driving and reduces the need to downshift as frequently to access useful response.
This does not turn the car into a completely different type of platform. The FA24 still supports the lightweight, naturally aspirated, rear-wheel-drive character enthusiasts expect. It simply provides more flexibility when exiting corners, passing, or accelerating from lower engine speeds.
The FA24 also belongs to a newer vehicle generation with its own electronics, exhaust layout, accessories, calibration, and chassis systems. It should not be assumed that FA20 parts will transfer directly, even when the components appear similar.
FA24 owners looking for a generation-specific intake can use the PERRIN cold-air system to improve the induction path while keeping the application focused on the second-generation BRZ and GR86.
PERRIN 22-23 Subaru BRZ/GR86 Cold Air Intake - Black (PERPSP-INT-335BK)
Important: The naturally aspirated FA24D used in the BRZ and GR86 is not the same installation package as the turbocharged FA24F found in other Subaru platforms. Confirm the exact engine code, donor vehicle, electronics, accessories, and intended application before ordering parts or planning a swap.
Performance and Everyday Response
The FA24 has the factory advantage in torque and overall pace. For a driver who wants stronger acceleration without immediately modifying the car, the second-generation platform is the more complete starting point.
The FA20 can still be engaging and capable, especially when the owner values momentum driving and is comfortable working within the engine’s powerband. Headers and proper calibration may reshape its response, but modification decisions should be evaluated against the cost of the complete car rather than treated as a guaranteed substitute for displacement.
The MAPerformance equal-length header is especially relevant to this comparison because it supports both first- and second-generation applications, giving FA20 and FA24 owners a common exhaust-side upgrade path for improving flow and midrange response.
MAPerformance Equal Length Header | 2013-2024 Subaru BRZ / Toyota GR86 / Scion FR-S
Peak dyno output does not describe the whole experience. Throttle response, torque curve, gearing, tire grip, ambient temperature, heat recovery, and calibration quality all affect how either engine performs on the road or track.
Track Use, Oil Control, and Heat Management
Track driving changes the comparison because repeated high-load operation exposes oiling, cooling, braking, and tire demands that may not appear during street use. Neither engine should be considered track-ready based only on a short list of bolt-on parts.
Owners should monitor oil level closely and evaluate oil temperature, coolant temperature, and pressure behavior under the vehicle’s actual duty cycle. The correct solution depends on the exact engine, tire grip, track layout, session length, ambient conditions, calibration, and driver pace.
For repeated high-load use, the MAP oil-cooler kit provides a cross-generation solution for 2013–2024 BRZ, FR-S, and 86 applications, making it a practical option when oil-temperature data shows that additional cooling capacity is needed.
MAP Oil Cooler Kit (13-24 BRZ/FR-S/86)
Second-generation FA24 builds can also address oil movement in the pan with the Cusco baffle plate, a more targeted option for owners preparing a GR86 or BRZ for sustained cornering loads.
Brakes deserve equal attention. Fluid condition, pad selection, rotor condition, cooling, pedal consistency, and tire capability all affect whether the car can repeat its performance safely. An engine-focused build that ignores braking and heat management is not a complete track plan.
When a second-generation build needs more brake capacity than a routine pad-and-fluid service can provide, the JDMuscle big-brake kit offers a complete platform-specific package with calipers, rotors, lines, pads, and installation hardware.
JDMuscle [22-25 BRZ/GR86] Big Brake Kit
Reliability and Used-Car Condition
Reliability depends more on the individual car than on a broad FA20-versus-FA24 reputation. Maintenance, oil level, calibration, operating temperature, previous repairs, and track history all matter.
When inspecting a used BRZ, FR-S, Toyota 86, or GR86, consider:
- Oil and coolant condition
- Service records and calibration history
- Evidence of overheating, leakage, or abnormal noise
- Compression and leak-down results when appropriate
- Previous track use and oil-monitoring practices
- Condition of the clutch, transmission, differential, brakes, and tires
- Aftermarket wiring, exhaust, intake, or ECU changes
- Recall documentation where applicable
Condition matters more than engine-family reputation. A properly maintained FA20 can be a better purchase than a neglected FA24, while a documented second-generation car may justify its higher entry cost through lower immediate repair needs.
Modification Potential
The FA20 benefits from a well-developed aftermarket and extensive community experience. Exhaust and calibration changes can alter its response, while suspension, brake, wheel, tire, and alignment upgrades can make better use of the chassis without changing the engine.
The FA24 starts with more usable torque, which may reduce the need for immediate engine modifications. Owners can focus first on tires, brake performance, alignment, cooling, and seat time before deciding whether additional output is necessary.
For either engine, forced induction, internal engine work, major fuel-system changes, or aggressive calibration should be planned with professional assistance. Fuel delivery, heat management, clutch capacity, transmission load, differential behavior, axle condition, emissions compliance, and serviceability must be considered together.
Can You Swap an FA24 Into an FA20 Car?
An FA24 swap should not be approached as a simple long-block replacement. The engines belong to different vehicle generations, with differences involving electronics, wiring, accessories, exhaust, fuel control, transmission integration, emissions equipment, and chassis systems.
A complete donor may reduce the number of missing components, but it does not eliminate the need for careful integration. Before purchasing an engine, confirm the ECU strategy, harnesses, immobilizer functions, mounts, oil pan, cooling connections, exhaust clearance, transmission compatibility, and legal requirements.
Compare complete installed systems rather than engine prices alone. A low-cost engine without the required electronics or accessories can become the most expensive version of the project.
Total Ownership Cost
The FA20 platform generally offers the lower entry price, but age and prior use can create additional maintenance needs. The FA24 platform usually costs more to purchase but provides stronger factory performance and may require fewer immediate modifications to achieve satisfying everyday pace.
A realistic ownership comparison should include:
- Vehicle or donor purchase price
- Maintenance history and current condition
- Cooling, oiling, brake, and tire requirements
- Calibration and emissions compliance
- Replacement-part availability
- Track consumables and inspection intervals
- Insurance, registration, and long-term serviceability
The best value is the car that fits the intended use without forcing the owner to rebuild every surrounding system immediately.
Which Engine and Generation Should You Choose?
Choose the FA20 Platform When:
- You want a more affordable entry into the BRZ and 86 chassis.
- You enjoy carrying momentum and using engine speed.
- You value a mature aftermarket and broad first-generation knowledge base.
- You are prepared to inspect age, maintenance, prior track use, and calibration history carefully.
Choose the FA24 Platform When:
- You want stronger factory torque and easier everyday acceleration.
- You prefer the refinement and performance of the second-generation BRZ or GR86.
- You want satisfying naturally aspirated pace with less immediate engine modification.
- Your budget supports the higher purchase price and generation-specific parts.
Common FA20 and FA24 Buying Mistakes
- Comparing peak output while ignoring torque delivery and vehicle condition
- Confusing the naturally aspirated FA24D with the turbo FA24F
- Assuming FA20 and FA24 electronics or accessories are interchangeable
- Modifying the engine before addressing tires, brakes, cooling, and maintenance
- Using internet power limits instead of measurements and professional evaluation
- Buying a track-used car without reviewing oil-monitoring and service practices
- Comparing engine prices instead of complete installed or ownership costs
Frequently Asked Questions
Is the FA24 faster than the FA20?
In factory BRZ and 86 applications, the FA24 provides stronger midrange output and better overall acceleration. The exact result still depends on vehicle condition, transmission, tires, calibration, and operating conditions.
Which engine is better for daily driving?
The FA24 is generally easier to drive in everyday situations because its additional torque reduces the need to keep the engine at higher rpm. The FA20 remains enjoyable for drivers who prefer a more momentum-focused character.
Which engine is better for track use?
Either platform can be used on track, but the answer depends on oil control, temperature behavior, brakes, tires, alignment, maintenance, and session demands. Engine choice alone does not determine track durability.
Can the FA20 make more power than the FA24?
Either engine can exceed factory output, but meaningful comparisons require a defined fuel, calibration, budget, torque target, parts list, and duty cycle. Peak dyno numbers do not establish durability.
Are FA20 and FA24 parts interchangeable?
Some categories may have related designs, but direct compatibility should never be assumed. Confirm the exact engine, generation, chassis, electronics, accessory layout, and manufacturer application before ordering parts.
Key Takeaways
| Decision Factor | What Matters Most |
|---|---|
| Driving character | The FA20 rewards momentum, while the FA24 delivers stronger and more accessible torque. |
| Purchase decision | Compare complete first- and second-generation cars rather than engine specifications alone. |
| Reliability | Maintenance, oil level, calibration, temperature control, and previous use matter more than reputation. |
| Track preparation | Oil behavior, cooling, brakes, tires, alignment, and inspection intervals must be planned together. |
| Swap planning | An FA24 swap requires generation-specific electronics, accessories, exhaust, and chassis integration. |
Related JDC Guides
Choose the FA20 when affordability, first-generation character, and a mature aftermarket fit the goal, or choose the FA24 when stronger factory torque and second-generation performance matter more. Build your second-generation setup with our 2022–2025 Subaru BRZ engine components, including engine hardware and supporting parts for street, track, maintenance, and naturally aspirated performance builds.
