'00 4.7L muffler question.
So... in 2008 I replaced the original muffler with a cheap Speedy generic muffler. Fuel mileage actually went down when I changed it and it's due to be changed again, but I hesitate as the bigger the hole and louder the muffler gets, the less fuel I actually use. Right now I'm getting about 600km to a tank with E10 fuel on highway driving. The last fill-up said I got 12.9L/100km
Bottom line is that the muffler is getting quite loud now and really does need to be changed, but I don't want to change it for one that'll create too much back pressure reducing my fuel economy. I was thinking of possibly getting a Magnaflow, with maybe the dual out tail pipes.
Anyone have any suggestions of a muffler that'll not affect my gas mileage?
2000 Grand Cherokee Laredo.