Turbo to Downpipe Gasket 4" for BMW B46 B48 N20 N26 N55 & Mini Cooper (18307581970)

The Turbo to Downpipe Gasket (4") is a direct replacement gasket for BMW N20, N26, N55, B46, and B48 turbocharged engines, as well as select Mini Cooper models. This gasket seals the connection between the turbocharger outlet and the downpipe, ensuring a leak-free seal and proper turbo efficiency.

Only one gasket is required per installation. This gasket is commonly used in 4" downpipe applications and directly replaces BMW part number 18307581970.

Key Features

• Turbo to downpipe gasket – 4" size

• Direct replacement for BMW part #18307581970

• Fits BMW N20, N26, N55, B46, B48 engines + Mini 2.0L B46/B48

• Ensures leak-free turbo-to-downpipe seal

• Sold individually (one gasket per turbo outlet)

• Replace whenever the turbo or downpipe is removed

Vehicle Fitment

BMW 3 Series

• 320i (2012–2018, N20/N26)

• 328i / 328i GT (2012–2018, N20/N26)

• ActiveHybrid 3 (2012–2015, N55)

• 335i / 335i GT (2012–2016, N55)

BMW 4 Series

• 428i / 428i Gran Coupe (2014–2016, N20/N26)

• 435i / 435i Gran Coupe (2014–2016, N55)

BMW 5 Series

• 528i (2012–2016, N20/N26)

• 535i / 535i GT (2014–2017, N55)

BMW X1

• X1 28i (2012–2015, N20)

• X1 28i (2016–2024, B46/B48)

BMW X3

• X3 28i (2013–2017, N20)

• X3 30i (2018–2024, B46/B48)

• X3 30e (2020–2024, B46/B48 PHEV)

BMW X4

• X4 28i (2015–2018, N20)

• X4 30i (2019–2024, B46/B48)

BMW X5

• X5 35i (2015–2018, N55)

• X5 40e (2016–2018, N20 PHEV)

BMW Z4

• Z4 28i (2012–2016, N20)

• Z4 35i / 35is (2012–2016, N54/N55)

• Z4 30i (2019–2024, B48)

Mini Cooper (2014–2024)

• Cooper S & JCW 2.0L (B46/B48)

Why Replace This Gasket?

This turbo-to-downpipe gasket is a crush-style seal and is not reusable. Reinstalling an old gasket can cause exhaust leaks, reduce turbocharger efficiency, and create unwanted noise. For best results, always replace with a new gasket during turbo or downpipe service.