Important thing to remember here is that decibels are on a logarithmic scale. Every 3db actually equals a doubling in sound pressure. So losing 8-10dbs as you are in most cases here is actually a huge difference, especially when it comes to those annoying drone frequencies.

40s sounds way much better

I very seldom click "like" on a video, but this side by side was so well executed that you earned it. The resonators built into the muffler clearly did their job knocking down drone

50 series is great for cruising and highway speeds, however if you want to be heard a block away before pulling up to a local car show it’s not the one I have the 50’s btw.

dam you cant ever beat the sound of a pair of flowmasters

The 50s sound best. Its what I'm running on my Oldsmobile 442 small block.

I used to have super 40s on my fox and they were faaaantastic, but were built like sh*t as the chambers rattled away after 2 years. A borla or magnaflow is the way to go. If i had another fox, even tho flowmaster suck in build quality, i would get another pair just for nostalgia. Nothing like a 5.0 with flowies

why have a muscle car without loud exhaust, that makes no sense!

Love the mustang 🐎! The 40s are for the young guys! When you get older it's not so appealing 😂

Thats the best side by side comparison ive ever seen, job well done. i also had the same problem with my 94 cobra with the collector dented i think its from not pulling the h pipe on even. I switched to equal length bbk headers and a pace setter x pipe with 40 series and 3inch flowmaster tailpipes for a fox like urs and it sounds raspy and rowdy. just took my mufflers to an exhaust shop and had the outlet swelled to match the 3inch tailpipes and it fit perfect i also switched to the band clamps myself for the same reason.From your video and your car i think you would like it. I wish exhaust companies would do what you did thats helpful on making a decision on exhaust because thats as important as wheels to guys like us.

"Nothing can ever be easy." 100% truth!

Thank you for the great comparison video, great editing. People often complain about how loud Flowmasters are while they choose the loudest Flowmasters lol it's an odd thing, but I like the tone of the 50s you installed, and 8-10db is a huge reduction

Sounds really good dude, I like the 50s. Great comparison

Thank you! Been looking for anything comparing the two types of FM 40s and 50s. Awesome and helpful video.

Excellent, comprehensive comparison. Thank you.

Thank for documenting and posting this- exactly the kind of information that I was looking for!

Great video! Thanks for this. I will definitely go with 50s

Great video, very scientific with the decibel meter and nice job documenting the install. Subscribed

Thank you so much for the video. Love the way to match a new bolt hole with the drill bits n chaser.

Wow...excellent video..thanks man..those 50's are really nice..