What benifits would my suv get if I install a flowmaster muffler?

I have a 2001 dodge durango 4.7 v8.|||It will sound alot louder. That's the main benefit. You will gain a small unnoticeable gain in fuel economy and while losing some low end torque you will gain some high end power. But far and away the main reason people use them is the louder exhaust note.