Not happy with fuel milage!!
I bought a Super 50 muffler to get better milage for I've got AFE air cleaner on now for a year.I also noticed that the muffler is as quiet as the old muffler.I didn't notice a fuel mileage gain as to today I had to go somewhere and put 117 miles on and only got 18.4 where as the same trip with old muffler I got 20.7 mpg. I've got a 2011 suburban w/3:42 gears which gives me low RPM's. Don't understand why because I put one of these on my 2500 pickup with same Engine but w/3.73 gear's