Ryco A1527 Engine Air Filter – Subaru WRX STI, Forester, Legacy & Outback
Clean Air for Consistent Engine Performance
Every engine relies on a steady supply of clean, unrestricted air.
The Ryco A1527 Engine Air Filter is designed to prevent dust, dirt and other airborne contaminants from entering the engine while maintaining the airflow required for efficient combustion.
It is a direct-replacement panel filter suitable for a wide range of Subaru petrol, turbocharged and diesel engines, including the EJ257-powered Subaru WRX STI Final Edition.
The Engine’s First Line of Defence
The air filter sits at the beginning of the engine’s intake system.
Without effective filtration, fine dust and abrasive contaminants can pass through the intake and contribute to wear within:
- Turbocharger compressor assemblies
- Cylinder walls
- Piston rings
- Valves and valve seats
- Airflow sensors
- Throttle bodies
- Internal engine components
Ryco’s filtration media is designed to capture these contaminants before they reach the engine.
Balanced Filtration and Airflow
A good air filter cannot focus exclusively on trapping dirt. It must also allow the engine to draw the volume of air it requires.
Ryco develops its air filters around three critical areas:
- Efficiency
- Filter life
- Airflow
The A1527 is designed to provide effective contaminant capture and strong dust-holding capacity without creating unnecessary intake restriction.
Its media structure retains dust within a complex path through the filter rather than allowing contamination to remain only on the surface.
Restoring Correct Engine Airflow
As an air filter becomes loaded with dirt, airflow through the intake can become increasingly restricted.
This may contribute to:
- Reduced throttle response
- Lower engine performance
- Increased fuel consumption
- Greater strain on the intake system
- Reduced turbocharger efficiency
- Incorrect airflow readings on sensitive engine-management systems
Replacing a dirty filter restores the airflow the engine was designed to receive.
A standard replacement filter will not create additional horsepower compared with a clean and correctly functioning filter. Its job is to restore and maintain proper airflow while protecting the engine from contamination.
Suitable for the Subaru WRX STI Final Edition
The A1527 is suitable for the 2.5-litre EJ257 engine used in the Subaru WRX STI Final Edition.
It provides a direct replacement for the standard engine air-filter element and is suitable for:
- Everyday road use
- Spirited driving
- Performance road vehicles
- Standard and sensibly modified engines
- Routine annual servicing
- Vehicles operating in dusty conditions
Because modified and imported vehicles may use different airboxes or intake systems, always confirm the filter dimensions before ordering.
Subaru Application Summary
The Ryco A1527 is listed for selected Subaru applications across the following model ranges.
Subaru Forester
Including selected:
- SG9 2.5 Turbo with EJ255
- SH5 2.0 with EJ204 and EJ205
- SH9 2.5 with EJ25 and EJ255
- SHH, SHD and SHN 2.0 diesel with EE20Z
- SHM 2.5 with FB25
- SHJ 2.0 with FB20
- SJ5 2.0 and 2.0 XT with FB20
- SJ9 2.5 with FB25
Approximate catalogue coverage ranges from 2005 to 2018, depending on engine, chassis and market.
Subaru Impreza, WRX and WRX STI
Including selected:
- GE3 1.5 with EL15
- GE7 2.0 with EJ204
- 2.0 diesel with EE20Z
- 2.5 WRX with EJ255
- 2.5 WRX STI with EJ257
- 2.0 WRX STI with EJ207
- GP7 2.0 with FB20B
- VA WRX STI 2.5 with EJ257
- UK Subaru WRX STI Final Edition with EJ257
Approximate catalogue coverage ranges from 2008 to 2021, depending on engine, chassis and market.
Subaru XV
Including selected:
- GP7 2.0 with FB20 engine
- Approximate catalogue coverage from 2012 to 2017
Subaru Legacy
Including selected:
- BL5 and BP5 2.0 with EJ202, EJ204 and EJ20Y
- BL5 2.0 GT
- BLE and BPE 3.0 with EZ30
- BL9 and BP9 2.5 with EJ25
- BL9 2.5 Turbo with EJ255
- BLD and BLP 2.0 diesel with EE20Z
- BM9 2.5 with EJ253 and EJ255
- Selected 2.0 GT applications with FA20
Approximate catalogue coverage ranges from 2003 to 2014, depending on engine, chassis and market.
Subaru Outback
Including selected:
- BHE 3.0 H6 with EZ30
- BPE 3.0 with EZ30
- BRD 2.0 diesel with EE20Z
- BRF 3.6 with EZ36D
- BS9 2.5 with FB25
- BSF 3.6 with EZ36D
- BSD 2.0 diesel with EE20Z
Approximate catalogue coverage ranges from 2000 to 2020, depending on engine, chassis and market.
Important Fitment Information
The supplier catalogue contains global applications, overlapping model entries and several open-ended production dates.
Some records displayed as running to 2025 refer to old “onwards” catalogue entries rather than vehicles genuinely remaining in production until 2025. Those dates should not be published as definitive UK fitment information.
Before ordering, confirm:
- Vehicle model
- Chassis code
- Engine code
- Existing filter dimensions
- Original airbox configuration
This is particularly important for Japanese imports, grey imports and modified vehicles fitted with aftermarket intake systems.
If you are unsure, please contact us with your registration number, VIN, engine code or a photograph of the existing filter before ordering.
Technical Specifications
- Manufacturer: Ryco
- Product type: Engine air filter
- Manufacturer part number: A1527
- Filter construction: Replacement panel filter
- Length: 221mm
- Width: 219.7mm
- Height: 34.5mm
- Product weight: Approximately 0.5kg
- Dust-holding media: Yes
- Direct replacement: Yes
- New Vehicle Warranty Protection: Listed by Ryco
What’s Included
- 1 x Ryco A1527 engine air filter
The airbox, intake pipework and fitting tools are not included.
Installation
The A1527 is designed as a direct replacement for the original air-filter element when fitted to a compatible standard airbox.
When replacing the filter:
- Open the vehicle’s airbox.
- Remove the existing filter and note its orientation.
- Inspect and carefully clean dirt from the lower airbox.
- Prevent loose debris from entering the open intake pipe.
- Position the new filter with the sealing edges sitting evenly in the airbox.
- Close and secure the airbox, checking that the seal has not moved or become trapped.
Never force the airbox closed over an incorrectly positioned filter.
This is a conventional replacement filter element. It should not be washed, oiled or treated as a reusable performance filter.
Service Interval
The air filter should be inspected and replaced in accordance with the vehicle manufacturer’s service schedule.
More frequent inspection may be required when the vehicle is regularly used in:
- Dusty environments
- Agricultural settings
- Off-road conditions
- Heavy traffic
- Areas with high levels of airborne debris
- Motorsport or performance applications
A filter that appears excessively dirty, damaged, wet or contaminated should be replaced regardless of mileage.
Recommended Service Combination
For compatible Subaru EJ257 applications, including the WRX STI Final Edition, the A1527 can be paired with:
- Ryco Z436ST SynTec high-efficiency oil filter
- The correct engine oil for the vehicle and intended use
- A new sump-plug sealing washer
- Additional fuel and cabin filters where required
This provides the basis for a properly matched Subaru service package rather than relying on unrelated universal components.
Why Choose Ryco?
Because an engine air filter must protect the engine without strangling its airflow.
Because a dirty or poorly fitted filter can affect performance, economy and long-term reliability.
And because the Ryco A1527 provides a properly sized, direct-replacement filter for a wide range of Subaru engines and airboxes.
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