Resonated or non-resonated cat-back exhaust: which one is right for your car?

Resonated or non-resonated: what are we talking about?

A resonator is a component in the exhaust system that dampens certain frequencies, the ones that create a hollow, intrusive sound. A resonated system has one; a non-resonated system does not. On a cat-back exhaust (the section after the catalytic converter), this choice often determines the car's sound character.

Drone: the real issue

Drone is the low, constant sound that appears at steady engine speed, typically on the highway or on the open road. It's what makes a system that sounds great in town become tiresome on a long drive.

• Resonated system: drone is significantly reduced, and the sound stays sporty but rounder.
• Non-resonated system: the sound is rawer and more pronounced, with a higher risk of drone at certain engine speeds.

Day to day

If your car is a daily driver, for commuting or family trips, the resonated system is generally the most comfortable choice: less fatigue on long drives, more relaxed passengers and a less noticeable cold start. A non-resonated system is perfectly livable if your trips are short or if character is your top priority.

The feel behind the wheel

The non-resonated system gives more presence when accelerating and revving: you can hear the engine, which heightens the sporty feel. The resonated system keeps that sportiness but in a more controlled way, with a fuller, less aggressive sound.

Which one should you choose?

• Choose resonated if the car is a daily driver, if you do long drives or if you want to stay discreet.
• Choose non-resonated if you want a pronounced sound and drone doesn't bother you.

Keep in mind that the final sound also depends on the engine, the downpipe, the factory muffler and any ECU tuning. Depending on the model, Milltek offers both versions: each part number's description specifies whether the system is resonated or not.

View Milltek cat-back exhausts

Find all part numbers in Hubshop's Milltek cat-back exhausts category, and keep your VIN handy to check compatibility with your vehicle.

Legal notice: not all part numbers are street legal. Non-homologated systems are reserved for motorsport use, on closed circuits or off public roads, and their use on public roads is prohibited.