Cometic C4574-040 MLS Head Gasket 101mm .040 for Subaru EJ255/EJ257 2.5L Turbo

Vehicle Fitment

• 2006-2014 Subaru Impreza WRX (AWD, 2.5L H4 EJ255 Version 2 DOHC 16V Turbo)
• 2004-2014 Subaru Impreza WRX STI (AWD, 2.5L H4 EJ257 DOHC 16V Turbo)
• 2015-2021 Subaru WRX STI (AWD, 2.5L H4 EJ257 DOHC 16V Turbo)
• 2013-2014 Subaru WRX (AWD, 2.5L H4 EJ255 Version 2 DOHC 16V Turbo)
• 2004-2013 Subaru Forester XT (AWD, 2.5L H4 EJ255 DOHC 16V Turbo)
• 2005-2012 Subaru Legacy GT (AWD, 2.5L H4 EJ255 Version 2 DOHC 16V Turbo)
• 2005-2009 Subaru Outback XT (AWD, 2.5L H4 EJ255 Version 2 DOHC 16V Turbo)
• 2004-2006 Subaru Baja Turbo (AWD, 2.5L H4 EJ255 DOHC 16V Turbo)
• 2006 Saab 9-2X Aero (AWD, 2.5L H4 EJ255 DOHC 16V Turbo)

Fitment Notes

• Designed for EJ255 Version 2 (2007+) and EJ257 (2007-2021) engine codes - these use a 101mm bore, distinct from the earlier EJ255 Version 1 and EJ257 (2004-2006) which use a 100mm bore (C4264 series)
• Do not use with early EJ255 Version 1 or 2004-2006 EJ257 engines - those require the C4264 series (100mm bore)
• The .040" compressed profile is a popular choice for standard performance builds and engine rebuilds with stock or lightly resurfaced head and block surfaces
• Saab 9-2X Aero (2006) shares the EJ255-based platform with the Impreza WRX - confirmed fitment
• Does not fit naturally aspirated EJ25 variants
• Sold individually - one gasket per listing (single cylinder bank); 2 required per complete engine build

Features

• Multi-Layer Steel (MLS) construction with three embossed stainless steel layers for durable, reliable sealing
• Outer layers coated with Viton fluoroelastomer rubber - heat resistant up to 482°F (250°C)
• No sealant required and no re-torque needed - installs dry on properly prepared surfaces
• Compatible with aluminum-to-aluminum head/block configuration of the EJ255/EJ257
• Load-controlled embossment design distributes clamping force evenly to minimize bore distortion
• Precision 101mm bore for accurate fitment on EJ255 Version 2 and EJ257 engines
• .040" profile suits stock-surface rebuilds and mild performance builds requiring a thin, reliable seal
• Race-proven - Cometic is the trusted sealing standard in Subaru performance builds worldwide

Specifications

• Part Number: C4574-040
• Gasket Type: MLS (Multi-Layer Steel) Cylinder Head Gasket
• Bore Size: 101mm
• Compressed Thickness: 0.040 inches
• Engine Compatibility: Subaru EJ255 Version 2, EJ257 (2007-2021), 2.5L DOHC 16V Turbo
• Layers: 3-layer stainless steel construction
• Coating: Viton fluoroelastomer (both sides of outer layers)
• UPC: 191070022884
• Position: Cylinder Head (single gasket)
• Drivetrain: AWD

Included Components

• 1x Cometic MLS Cylinder Head Gasket (C4574-040)

Product Description

The Cometic C4574-040 is a Multi-Layer Steel cylinder head gasket engineered for the Subaru EJ255 Version 2 and EJ257 turbocharged engines. With a 101mm bore and a 0.040-inch compressed thickness, it is one of the most commonly selected options for standard WRX and STI engine rebuilds - delivering a clean, sealant-free seal on stock or lightly prepared head and block surfaces. It fits the 2006-2014 Impreza WRX, 2004-2021 WRX STI, Forester XT, Legacy GT, Outback XT, Baja Turbo, and the 2006 Saab 9-2X Aero. It installs dry with no sealant or re-torque required.

Three embossed stainless steel layers with Viton-coated outer surfaces provide long-term sealing reliability under the elevated thermal and cylinder pressure demands of boosted EJ255 and EJ257 applications. Important: this gasket uses a 101mm bore for the EJ255 Version 2 and EJ257 (2007+) platform and is not compatible with the earlier 2004-2006 EJ257 or EJ255 Version 1 engines, which require the C4264 series (100mm bore). For the builder seeking a proven, thin-profile solution for a WRX or STI rebuild, the C4574-040 is a trusted standard choice.