This high-grade lightweight titanium system, finished with hand-crafted carbon-fibre tailpipes, weighs in at 35% lighter than stock and features a pair of collectors cast in the in-house foundry. The Slip-On Line (Titanium) comes with a specially developed Akrapovic control kit for a complete sound experience. The sound character offers a rich tone at normal cruising, rising to a deep sporty sound when the M3/M4 is driven more dynamically. It serves up a perfect sound at all rpms, delivering comfort and sportiness in one exhaust. A ground-breaking octagonal shape has been fashioned from lightweight titanium with a carbon-fibre outer sleeve for the tailpipes, and for more traditional buyers there is the classic cylindrical design.

The system delivers power increases of 8.0 kW (10.9 hp) at 6,000 rpm and a torque gain of 13.9 Nm at 5,000 rpm when tested on the Akrapovic dyno against a BMW M4 Competition with a standard stock exhaust. Remapping is not needed for this configuration, and it fits all vehicles (OPF and non-OPF), but the ECE certificate is valid only for cars equipped with an OPF filter.

Optional link pipes and downpipes are available for customers looking to change the exhaust for closed-circuit usage. An optional Akrapovic Sound Kit is also available. With the installation of the optional link pipes, downpipes, and Akrapovic Sound Kit, ECE type approval of the Slip-On Line (Titanium) is no longer valid. An optional hand-crafted carbon-fibre rear diffuser is also available to add an extra visual impact to the Akrapovic tailpipes.

The exhaust system also fits xDrive models.

The Slip-On Line (Titanium) exhaust system is ECE type approved for cars equipped with an Otto/gasoline particulate filter.