Flowmaster 42543 2.5-Inch Inlet & Outlet 40 Series Muffler Review

If you have a v8 f150 I would probably go for something more powerful. It wasn't difficult to install at all. But a little quieter than I would like. But definitely a noise difference between this and a stick muffler.

I bought two 40 series for my 2015 F150 5.0L, headers and dual rear exhaust installed with them. The sound of the truck is very good, mostly loud, but sometimes turns into a quiet hum. When I step on the gas it sounds loud, although no complaints here.

For what you pay it's not that bad. This is better for those looking for a suitable muffler replacement but don't want to look obnoxious. The sound of the muffler is more aggressive, but not too loud. It's pretty close to the drain with a deeper rumble. I recommend it.

Matches my '98 Dodge Dakota perfectly and sounds fantastic. A nice low rumble that makes the otherwise modest V6 sound like a V8 when idling. If you own a truck and want it to sound a little more brutal on a budget, the Flowmaster 40 series is the way to go.

Overall very happy with this muffler. My F-150 definitely has a more aggressive sound after installation. I expected it to have a deeper, growling sound, especially at idle. It sounds louder but not what I expected, especially from the YouTube videos I watched. Still, it was worth spending a few bucks more for a Flowmaster instead of an OEM spare.

Product as advertised, sounds much better than stock in my opinion. I have a 2006 F150 with a 5.4 liter V8 Triton engine and am happy with the sound quality of this product. It's worth noting that the black color is pretty bad here. In no time at all it was gone, revealing the silencer's silvery metal housing. The sound is much more aggressive, but the buzz that I like isn't there at all.

I removed the case silencer and left the resonator in for about 4 years. The sound was loud but hoarse, not the deep rumble I was looking for. After watching a lot of YouTube videos and reading reviews and ratings, I decided on two Flowmaster 40 series, removed Reso and Day and Night from my old setup. Cold starts are loud, aggressive and deep. They have a hum around 1750-1900 rpm, but that's easy to take. My wife and kid didn't complain about the 3 hour drive we took the other day. When you…