I have a Hemi in my Jeep Wrangler JKU. I had Flowmaster Pro series headphones, which sounded great, but the rumble at highway speeds was unbearable. Switched to this series 50 and oh what a difference. I can start my jeep without my neighbor hearing me, and it sounds great under acceleration, but immediately quiets down as it speeds up. The only thing I wanted was for the Flowmaster to still do the version with inlet and outlet staggered on the same side. Update June 2020, description says 16β¦