Any truck drivers willing to do an exhaust experiment?

[mpgking]

I had a 2008 jeep grand cherokee with the 3.7L 12 valve single over head cam only producing 210 HP and 235 TQ stock. The stock exhaust tubing was already 2-1/2 inchs. a 2-1/2 inch pipe is good for about 250 HP. I changed nothing but the muffler to a magnaflow and gained 1-2 MPGS.I did`nt have any problems with low end loss but I kept the stock tubing. As far as weight I don`t really see saving on gas from the weight differance of the exhaust system.