Cometic Toyota B58/B58H .042in MLX Head Gasket
Ships from the brand or distributor, usually in 3–7 business days
Make sure this fits your car
Fits: BMW M340i (G20), M440i (G22/G23/G26), M240i (G42), Z4 M40i (G29), 540i (G30, 2020+), X3 M40i (G01, 2020+); Toyota GR Supra 3.0 (A90/A91) (B58).
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- 30-day returns on unused parts
- Fitment help before you buy
When you build a B58 for big boost, the head gasket is one of the first parts to reconsider. Cometic's MLX gasket is a multi-layer stainless design with a stopper layer that spreads the clamping load and coatings that help it seal under high cylinder pressure. It's made for the second-generation B58 (2020 and later) with the 83 mm bore.
What you get
- .042-inch compressed thickness, a step thicker than the .040 version.
- 83 mm bore to match the B58.
- Multiple stainless steel layers with an integrated stopper layer for even load distribution.
- Cometic's sealing coatings for high-boost, high-compression or fully built engines.
Good to know
- Cometic offers this gasket in several thicknesses. Picking a thicker or thinner one is how a builder adjusts compression ratio and piston-to-head clearance, so choose it with your engine builder.
Brand: Cometic Gasket · Part #: C14144-042
Ships from the brand or distributor, usually in 3-7 business days.
BMW M340i (G20), M440i (G22/G23/G26), M240i (G42), Z4 M40i (G29), 540i (G30, 2020+), X3 M40i (G01, 2020+); Toyota GR Supra 3.0 (A90/A91) (B58).
| Model | Chassis | Years | Engine | Fits |
|---|---|---|---|---|
| M140i | F20/F21 | 2016–2019 | Gen 1 B58 | |
| M240i | F22/F23 | 2016–2021 | Gen 1 B58 | |
| 340i | F30/F31/F34 | 2016–2019 | Gen 1 B58 | |
| 440i | F32/F33/F36 | 2017–2020 | Gen 1 B58 | |
| 540i | G30/G31 | 2017–2019 | Gen 1 B58 | |
| 740i | G11/G12 | 2016–2019 | Gen 1 B58 | |
| X3 M40i | G01 | 2018–2019 | Gen 1 B58 | |
| X4 M40i | G02 | 2019 | Gen 1 B58 | |
| 640i GT | G32 | 2018–2019 | Gen 1 B58 | |
| M340i | G20/G21 | 2019–2024 | Gen 2 B58 (TU) | |
| M440i | G22/G23/G26 | 2021–2024 | Gen 2 B58 (TU) | |
| M240i | G42 | 2022–2024 | Gen 2 B58 (TU) | |
| Z4 M40i | G29 | 2019+ | Gen 2 B58 (TU) | |
| GR Supra 3.0 | A90/A91 | 2020+ | Gen 2 B58 (TU) | |
| 540i | G30/G31 | 2020–2023 | Gen 2 B58 (TU) | |
| 740i | G11/G12 | 2020–2022 | Gen 2 B58 (TU) | |
| X3 M40i | G01 | 2020+ | Gen 2 B58 (TU) | |
| X4 M40i | G02 | 2020+ | Gen 2 B58 (TU) | |
| X5 xDrive40i | G05 | 2019–2023 | Gen 2 B58 (TU) | |
| X6 xDrive40i | G06 | 2020–2023 | Gen 2 B58 (TU) | |
| X7 xDrive40i | G07 | 2019–2022 | Gen 2 B58 (TU) | |
| 840i | G14/G15/G16 | 2019+ | Gen 2 B58 (TU) | |
| INEOS Grenadier | Station Wagon/Quartermaster | 2023+ | Gen 2 B58 (TU) | |
| M340i | G20/G21 | 2025+ | Gen 3 B58 (48V) | |
| M440i | G22/G23/G26 | 2025+ | Gen 3 B58 (48V) | |
| M240i | G42 | 2025+ | Gen 3 B58 (48V) |
Not sure? Email sales@b58racing.com with your VIN.
- Ships from the brand or distributor, usually in 3–7 business days.
- Shipping is charged at the carrier's rate, shown at checkout. Orders over 70 lb ship by freight for a flat $99.
- Unused parts can be returned within 30 days. Some items are marked no-refund in their description.
Full details are on our shipping and returns page.
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