Originally Posted By: Wolf359
The manufacturers slowly switched over to stainless steel so OEM mufflers last a long longer. Back in the 80's you'd replace a muffler every two years or so which kept shops like Midas in business. Now pretty much all those muffler shops are just general maintenance shops as mufflers last a lot longer than they used to. With that said, I replaced the factory muffler about 5 years ago with a Walker muffler, just replaced it again as the old one finally rusted out. OEM lasted about 9 years. Got the lifetime warranty on the Walker so the 2nd one didn't cost me anything besides shipping.
IMO not for most of the imported automobiles such as Honda or Toy...they still on thick steel mufflers (not sure about whose supplying those brands, but for the longest time, Mazda got their supply OEM mufflers from Senkei)
Truth is, with lowered sulphur in gasoline (now @ 30ppm, as opposed to more than 100ppm (some recorded as high as 230ppm in late 90s, from petrocan), emission controlled cars with CAT now converts less exhaust gas into sulphuric acid vapour per miles than, say, back up to and including the 90s.
As a result: regardless of stainless steel or high grade steel, muffler lasted much, much longer (citing that my dad's 7th gen civic still on it's original factory muffler and piping for 15 yrs now and going).
muffler shops pretty much part of the history nowadays, unless they convert their business model to doing specialty installation/products.
Q.