Milltek Sport Cat-Back Exhaust - 2020-2025 Audi S8 D5

This Milltek Sport cat-back exhaust fits the 2020-2025 Audi S8 (D5) with the 4.0 liter twin-turbo V8. For the D5 S8, Milltek offers 80 mm non-resonated and resonated systems that run from the particulate filters back, with GT-115 tips in five finishes. Each system is built for this exact chassis, so it follows the factory routing, hangs from the stock mounts and keeps the ground clearance of the original exhaust. Compared with the factory steel parts it is lighter, flows more freely and gives the engine a clearer, stronger voice under load, without the harsh highway drone of a cheap straight pipe. The Audi S8 D5 parts are T304L stainless steel with mandrel-bent tubing, which keeps the pipe at full size through each bend and resists corrosion for years. It bolts on with the factory hangers and clamps, with no cutting or welding needed. It swaps the factory exhaust from the catalytic converters back, using 80 mm (3.15 in) T304L stainless steel pipework, and bolts to the factory mounting points.

How to Choose

Start with the Sound. Non-Resonated (Louder) drops the resonator for a louder, rawer note. Resonated (Quieter) keeps a resonator for a deeper tone with less drone when cruising.

Then pick an Exhaust Tip Finish: Polished (bright polished stainless), Cerakote Black (a black Cerakote ceramic coating), Brushed Titanium (a brushed titanium finish), Carbon Fiber (carbon fiber outer sleeves), Burnt Titanium (a heat-blued burnt titanium finish). The finish changes the look only, not the sound.

The Add Downpipe option bundles a Milltek downpipe with the cat-back. No Downpipe keeps your factory downpipe. Catless Downpipes has no catalytic converter. It is for off-road and track use only and needs an ECU remap. Catted Hi-Flow Sports Cat Downpipes keeps a high-flow sports catalytic converter. Milltek recommends an ECU remap with it. You can also buy them on their own from the downpipes for the Audi S8 D5.

Features

• 80 mm (3.15 in) T304L stainless steel pipework
• Mandrel-bent and made to bolt to the factory mounting points
• 5 tip finishes
• Catted and catless options explained in How to Choose

What's Included

• Right connecting pipe (to Milltek OPF back system)
• Left and right lower downpipes
• Left and right front silencer replacement pipes
• Active center section
• Left connecting pipe
• Left and right rear silencers
• The downpipe you choose, if you add one

Specifications

Fitment Notes

• Fits the 2020-2025 US-market Audi S8 (D5). Every US S8 is the long-wheelbase car.
• The downpipe add-ons are race products and need an ECU remap; the catless version is for off-road or track use only.
• Catless parts remove the catalytic converter. They are sold for off-road and competition use only and are not legal on public roads in the US.

Questions about fitment? Call (310) 231-0292 or text (310) 886-3111.