I'm in the process of replacing the front muffler on my W124 and after getting the old one off I noticed it was significantly heavier than the newer one. So I weighed them. The old muffler (minus the pipes, which I had to cut off) is 21.2 lbs. The new one, with pipes, is only 13.6. I've never noticed such a discrepancy before. Is the original equipment muffler that much more well built, or did it just accumulate a lot of combustion materials over the years?