Which Milltek system fits your X3 M?
Start with the build date and market. UK and European X3 M Competition models with an OPF/GPF have a filter-back system, a downpipe-back system and Active Valve Control, listed separately for pre-LCI cars (2019-21) and LCI cars (2022 on). The LCI cars also have a GPF/OPF bypass.
North American and rest-of-world LCI cars (2022 on) have a single cat-back system, listed separately from the parts for UK and European cars.
Filter-back or downpipe-back for the X3 M?
A filter-back system replaces the exhaust behind the factory particulate filter, leaving the downpipes and filter in place. A downpipe-back system replaces more of the exhaust, from the downpipes rearward, and like most downpipe upgrades it will usually need an ECU remap. The GPF/OPF bypass is a louder, motorsport-oriented part rather than a road-focused upgrade.
Systems come resonated, the quieter choice with less drone, or non-resonated, with GT-115 tips or JET-115 carbon fibre; see the tip styles page. The X4 M collection has a similar range for the G02.
Buying X3 M parts from Milltek Exhaust Shop
Enter your reg in the lookup at the top of the page to see only parts that fit your X3 M. We deliver free in the UK and ship worldwide, accept PayPal and Klarna, and offer fitting at our Stoke-on-Trent workshop.