Re: 4" Turbo back Exhaust installed on a 7.3L
Found another down side to the new exhaust system. My transmission temps are as high as I've ever seen them on a long hot climb. I'm guessing the new exhaust comes much closer to the transmission and cooling lines so it's heating everything up. In fact the new exhaust is within a 1/4 inch of the transmission now. I'm going to wrap the exhaust from the turbo back and see if that helps.
Yes, it's still worth it. I'm sure I've gained one mpg, and maybe even two. Best part is much less downshifting on the smaller grades. My van used to downshift all the time. Mostly due to my gearing 3.73 with 33" tires makes for around 1600 to 1700 rpm at 60mph. Too low for the van to pull the hills. Now you hear the turbo spool up, sometimes see a little black smoke, and the van just motors up.