The difference is that the dual exhaust system has two exhaust systems on one vehicle. Meaning, when modifying your exhaust, never start from the front of your turbocharged vehicle with a downpipe or with 280z headers on your naturally-aspirated platform, you will create a bottleneck in the flow. By starting with a cat-back first, your exhaust gases will flow more freely if the rest of your system is stock.

Considering cat-back exhausts replace more restrictions, they typically offer increased performance and noise compared to axle-back systems