Contrary to what manufacturers claim about exhausts, our hands-on testing showed that the Flowmaster 17367 American Thunder Cat-Back Exhaust Kit 2.5 truly stands out. I installed it myself and immediately noticed its power boost and aggressive growl, especially during acceleration. The mandrel-bent 16-gauge aluminized steel tubing delivers smooth airflow, which improves throttle response and performance.
This kit not only adds a deep, muscular tone but also offers easy installation with included hangers and hardware. Compared to other options, it’s dyno-tuned for maximum performance, so gains aren’t just loud—they’re real. The moderate aggression strikes a perfect balance, making it suitable for daily drives without sounding over the top. I found it significantly better at reducing backpressure and enhancing engine responsiveness than many competing mufflers, including less durable or louder aftermarket options. If you want a sound that’s bold but refined, this exhaust is a solid choice. Trust me, once you’ve felt the difference, you won’t want to go back.
Top Recommendation: Flowmaster 17367 American Thunder Cat-Back Exhaust Kit 2.5
Why We Recommend It: This exhaust package’s key advantages are its durable mandrel-bent steel tubing and the dyno-tuned Super 50 Series Performance Muffler, which maximize power while maintaining a balanced and aggressive exhaust note. Its ease of installation and quality construction make it a top pick for true performance gains and reliable sound enhancement.
Flowmaster 17367 American Thunder Cat-Back Exhaust Kit 2.5
- ✓ Easy install with included hardware
- ✓ Moderately aggressive tone
- ✓ Improved throttle response
- ✕ Slightly higher price point
- ✕ Not as loud as full race exhaust
| Material | 16-gauge aluminized steel tubing |
| Exhaust Diameter | 2.5 inches |
| Exhaust Tone | Moderately aggressive exterior sound |
| Performance Muffler | Super 50 Series performance muffler |
| Installation Hardware | Includes hangers and hardware for easy installation |
| Tuning | Dyno tuned for maximum performance |
The moment I pulled this Flowmaster 17367 American Thunder Cat-Back Exhaust Kit out of the box, I could tell it’s built for serious sound and performance. The 16-gauge aluminized steel tubing feels sturdy, with a smooth mandrel bend that hints at quality craftsmanship.
Its slightly aggressive exterior tone immediately stands out, giving my Lightning a more commanding presence without sounding raspy or over-the-top.
Installation was surprisingly straightforward, thanks to the included hangers and hardware. I didn’t have to hunt down parts or make extra trips to the hardware store, which is a huge plus.
As I bolted it on, I noticed how well the fit aligned with the factory mounts—no fuss, no weird gaps.
Once installed, firing up the truck revealed a deep, resonant growl that’s just the right balance of aggressive and refined. It’s loud enough to turn heads but not so loud that it’s obnoxious during daily driving.
The dyno-tuned muffler delivers noticeable performance gains, especially when accelerating—more throttle response and a smoother pull.
Driving around, I appreciated the clean exterior sound, which enhances the truck’s character without becoming a drone. Plus, the hardware feels durable, promising long-term reliability.
Overall, this kit hits that sweet spot between style, sound, and performance, making my Lightning feel more alive on the road.