I just read a post that said a magnaflow rusted out. Is the SS a low grade so it doesn't last very long? My parts store is trying to sell me a SS welded Thrush. Would it last any better? I assume the sound would be similar to a flowmaster. Looked for a sound clip but couldn't find much.

 

magnaflow is 409ss it will surfice rust but shouldnt rust thru.A easy way to cheak ss is with a magnet if the magnet sticks its 409 if not its 304

 

The one guys who did was 6yrs old, not sure why it did, but maybe it was too much salt from previous winters or submerging into water to dock a boat.

 

https://www.f150online.com/forums/ex...s-problem.html

If this is the post you are talking about, the guy states that this is not a stainless steel muffler.

 

The BIGGEST cause of mufflers rusting out is people who just drive around in town for short trips. The condensation doesn't completely evaporate from inside the exhaust system because the vehicle isn't running long enough to get hot! I used to see this all the time when I worked at a muffler shop in the eighties. Little old ladies who "only drive to church and the store" were 50% of the customers!

Of course, exhaust technology and materials have changed ALOT since then...

 

So the new Magnaflows come as an unpolished or polished stainless? Seems odd to me that it would cost $30 or so in the difference for one or the other if they are both made of the same material. A big tumbler and some media is all it would take to polish them after they are built. Some of the spots on the web site say stainless and some say aluminized. I emailed the company but haven't yet received a reply as to which the cheap ones actually are. Factory one lasted 8 maritime, salty winters so I'd like to get something to replace it as good of quality.

 

The polished stainless muffler is T-304 which will not rust at all, the T-409 stainless natural finish will not break apart but may surface rust over a long period of time.