Cometic MLX Head Gasket (Single)
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Cometic MLX Head Gasket (Single) – Subaru EJ25 (to 2006) – 101mm Bore
The Cometic MLX Head Gasket is a multi-layer stainless steel replacement for the factory head gasket on Subaru 2.5L EJ25 engines up to 2006: the EJ25D, EJ251, EJ252, EJ253 and EJ255 Version 1, and the 2004–2006 EJ257 from the GD Impreza WRX STI. It has a 101mm round bore and comes in a choice of compressed thicknesses, so you can match the stock deck height or set the compression ratio on a rebuilt engine.
Cometic's MLX (Multi-Layer Xtreme) gasket adds a fold-over stopper layer around each bore. The stopper acts as a torque-limiting surface that stops the combustion seal from yielding, which suits high-boost engines with high cylinder pressure. Coated, embossed layers seal the coolant and oil passages.
Options
Compressed thickness: 0.81mm (.032"), 1.12mm (.044"), 1.52mm (.060"). Thicker gaskets lower compression; match the thickness to your engine builder's spec.
Note: Sold individually – an EJ engine needs two, one for each head. For EJ255 and EJ257 engines from 2007, choose the Version 2 gasket instead. Installation by a professional is recommended.
Features
- Cometic MLX multi-layer stainless steel construction
- Fold-over stopper layer around each bore stops the combustion seal yielding under high boost
- 101mm round bore
- Choice of compressed thickness to suit stock or built engines
- Installed dry – no sealant needed
Kit Contents
- 1 x Cometic MLX cylinder head gasket
Need help confirming fitment? Contact our team at sales@chicaneaustralia.com.au.
Product
- Brand
- Cometic
- Part number(s)
- C4578-032, C4578-044, C4578-060
Details
- Product
- MLX cylinder head gasket
- Construction
- Multi-Layer Xtreme (MLX) stainless steel with fold-over stopper layer
- Engine
- Subaru EJ25D, EJ251, EJ252, EJ253 and EJ255 Version 1, and EJ257 2004–2006
- Bore
- 101mm, round
- Compressed thickness
- 0.81mm (.032"), 1.12mm (.044"), 1.52mm (.060")
- Layers
- 3 layers at 0.81mm; 4 layers at 1.12mm; 5 layers at 1.52mm
- Sold as
- Single gasket (two needed per engine)
Contents
1 x Cometic MLX cylinder head gasket (101mm bore)

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