How can the very same vehicle provide two different soundtracks depending on where it’s sold? While some automakers do offer optional exhaust systems for their performance cars that generate a more aggressive note, there’s also another possible explanation.

As emissions regulations in Europe are getting stricter, automakers have no other way but to adapt by installing petrol particulate filters to make their cars comply with the more stringent regulations.

The Audi RS Q8 is a relevant example since the Euro version has a significantly toned down noise compared to the version sold in the Middle East or North America. friend Auditography had the opportunity to film a non-EU example of Audi Sport’s flagship SUV on the streets of Doha in Qatar, revving the twin-turbo 4.0-litre V8 to demonstrate the meaner exhaust note.

Gallery: Audi RS Q8 without PPF

It’s worth mentioning this murdered-out Audi is a fully loaded version with every possible box on the options list ticked, including ceramic brakes and a carbon fibre package. It’s wearing a sinister Orca Black Metallic paint contrasted only by the red brake calipers, a look that carries over inside the predominately black cabin with red stitching.

While Europeans are missing out on the SUV’s beefier exhaust note, we’re trying to see the glass half full. Without a petrol particulate filter, there probably wouldn’t even be an RS Q8 on the Old Continent. It’s there for a good reason as it cuts down on the amount of CO2  sent into the air by trapping the unwanted particles.

An in-depth explanation of how PPFs work and why they’re important can be found in this document published by the Association for Emissions Control by Catalyst. If you haven’t heard of it, it’s a non-profit scientific association of European companies involved in the development of engine exhaust emissions control systems.