Milltek Cat-back Exhaust for BMW X3 X3M/X3M Comp (G01) 3.0 (ROW & North American S58 Engine - LCI only) (2022 and Later) (2022 onwards) – Sharper Sound, Reduced Back Pressure
This is Milltek's cat-back system for the BMW X3 X3M/X3M Comp (G01) 3.0 (ROW & North American S58 Engine - LCI only) (2022 and Later). It replaces everything from the factory catalytic converter rearward with wider-bore pipework, a re-profiled mid-pipe and silencers tuned specifically for this platform, cutting back pressure and sharpening the exhaust note. The factory catalytic converter stays in place, so the car's emissions hardware is left as standard. It's offered in non-resonated or resonated versions and 5 tailpipe finishes, so you can pick the setup that suits how the car's used.
It's aimed at owners who want a noticeably different sound and a genuine, if modest, flow improvement without touching anything upstream of the cat: a straightforward bolt-on that doesn't need a remap or any other supporting mods to enjoy.
Specifications
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System Type: Cat-back
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Pipe Diameter: 80mm (3.15")
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EC Approved: No
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Fitting Time: approx. 2 to 3 hours (Milltek figure)
Key Features
- Made from T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration
- Mandrel-bent pipework keeps a constant diameter through every bend for unrestricted flow
- 80mm (3.15") pipework
- Replaces the standard exhaust from the catalytic converter back, so the factory cat is retained
- Choice of 5 tailpipe finishes: GT-115 Burnt Titanium, GT-115 Cerakote Black, GT-115 Titanium, JET-115 Carbon Fibre, GT-115 Polished
- Resonated (quieter) or non-resonated (louder) versions
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- BMW X3 X3M/X3M Comp (G01) 3.0 (ROW & North American S58 Engine - LCI only) (2022 and Later) (2022 onwards)
- BMW X3 X3M/X3M Comp (G01) 3.0 (with OPF/GPF S58 Engine - Pre LCI only) (2019-2021)
- BMW X4 X4M/X4M Comp (G02) 3.0 (ROW & North American S58 Engine - LCI only) (2022 and Later) (2022 onwards)
Not every version fits every car in this list. Check the fitment shown for the option you select.
Not suitable for: the BMW X3 X3M/X3M Comp (G01) 3.0 (with OPF/GPF S58 Engine - LCI only), which needs the Milltek Downpipe-back Exhaust BMW X3 X3M & X3M Comp G01 3.0 (with OPF/GPF S58 Engine - LCI only) 22+.
Installation
Milltek quotes a fitting time of approx. 2 to 3 hours. We recommend professional fitting on a ramp. Once fitted, check the tailpipe alignment and re-check all clamps after the first few hundred miles.
Upgrade Further
Also available from Milltek for this car: Milltek Secondary Catalyst Bypass BMW X4 X4M & X4M Comp G02 3.0 (ROW & North American S58 Engine - LCI only) 2022 & Later 22+.
What's the difference between the resonated and non-resonated versions?
The resonated version adds extra silencing for a quieter, more refined tone. The non-resonated version leaves it out, so it is louder and more aggressive.
Which tailpipe finishes are available?
You can choose from: GT-115 Burnt Titanium, GT-115 Cerakote Black, GT-115 Titanium, JET-115 Carbon Fibre, GT-115 Polished. The finish is cosmetic and does not change the sound.
Will it fit the BMW X3 X3M/X3M Comp (G01) 3.0 (with OPF/GPF S58 Engine - Pre LCI only)?
Yes. Milltek lists this part for the BMW X3 X3M/X3M Comp (G01) 3.0 (with OPF/GPF S58 Engine - Pre LCI only) as well as the other models in the fitment list above.
Does it fit the BMW X3 X3M/X3M Comp (G01) 3.0 (with OPF/GPF S58 Engine - LCI only)?
No. For that car, choose the Milltek Downpipe-back Exhaust BMW X3 X3M & X3M Comp G01 3.0 (with OPF/GPF S58 Engine - LCI only) 22+.
Is it road legal?
Milltek does not list EC approval for this part. Any exhaust used on the road must still meet noise and emissions rules, so check the requirements where you live.
Do I need a remap?
No. It fits behind the factory catalytic converter, so no software changes are needed.
Does it keep the factory catalytic converter?
Yes. It fits behind the factory catalytic converter, which stays in place.
How long does it take to fit?
Milltek quotes approx. 2 to 3 hours.
What is it made from?
T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration better than lower grades.
