Milltek Sport Cat-Back Exhaust for BMW 1 Series M140i (B58) F20/F21 | 3.0-inch Stainless Steel | GT90 Tips | Resonated or Non-Resonated | Valved Options

BMW 1 Series M140i B58 Performance Rear System by Milltek Sport

Give your turbocharged straight-six 1 Series the soundtrack and flow it deserves. This Milltek Sport rear system for the F20 and F21 M140i delivers a richer tone, faster rev pick up and a meaningful weight reduction compared to the factory set-up. Built for drivers who want premium sound quality and UK engineering, it is the go-to upgrade for enthusiasts chasing a sharper, more engaging drive on road or spirited B-road blasts.

We run Milltek on our own cars and our customers consistently praise the fit, finish and the addictive, refined note. Designed and produced in Britain to ISO 9001 standards, the attention to detail is exactly what you would expect from a brand with decades of performance exhaust know-how.

Key reasons to upgrade

• Improved throttle response and freer-revving feel from flow-optimised 76 mm pipework
• Noticeable weight saving versus the OE system for a more agile rear end
• Low back pressure design that maintains torque while enhancing top-end pull
• Aero-grade 304 stainless steel throughout for durability and resistance to discolouration
• Consistent bore with mandrel bends for smooth gas velocity
• Twin GT90 90 mm outlets for an OEM plus look that fills the valance perfectly
• Engineered and assembled in the UK with rigorous quality control

Sound choices and valve control

Tailor the volume and character to your build. Choose a silenced mid section for a more subtle, daily-friendly soundtrack or go non-silenced for a louder, more aggressive tone. Selected versions feature valve control so you can enjoy a deeper note on demand while keeping things civil when you need to.

Fitment

Compatible with BMW 1 Series M140i F20 and F21 hatchback models, three-door and five-door, with the B58 3.0 turbocharged engine. Direct-fit cat-back layout designed for road cars, fast road projects and OEM plus upgrades.

Technical details

• Bore size: 76.20 mm, 3.00 inch
• Tailpipe style: Twin 90 mm GT90
• Material: Type 304 stainless steel, including silencers

Part numbers

• SSXBM1040
• SSXBM1041
• SSXBM1042
• SSXBM1043
• SSXBM1044
• SSXBM1045
• SSXBM1046
• SSXBM1047
• SSXBM1048
• SSXBM1049

Warranty

Milltek two year warranty.

Professional fitting

Want it installed properly the first time. Book expert fitting with MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk and our team will be happy to help.

Search-friendly terms to help you find the right upgrade

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