It is a true mod.

 

Thanks Hydra but I didn't need to reset.

I just plugged it in, re secured the TCM to the body, and drove off. As stated earlier, the RPMs dropped by about 300-400 RPM. I can now tach 2k at 75, and maybe 1600 at 65 with 3.55's and 31" tires. The downshift from the 2nd O/D to 3 takes a huge push on the throttle, but agan this is only necessary if you need immediate power. Slower acceleration needs only require a moderate throttle press. The 2nd O/D for me was at about 1600 and when I needed to jump up to get over a hill to maintain 65 it would jump to about 3k. My Overhead has been amazingly accurate so I don't bother hand calculating anymore but it was reading 18-20 MPG. Thats an easy 3-4 MPG increase for me. Like I stated earlier, if you're within the years of 2001-2002 with a 4.7, this WILL work.

 

Hey MoparMan1991, I see from your sig that you live in Nebraska. From what I understand it's nearly flat throughout the state. You shouldn't have the troubles I had with my Jeep TCM experiment.

 

This is nearly accurate, however, we still do have large hills in the area. The Loess Hills are over in Iowa where I am from, and those hills thin out to our side of Nebraska a little bit. But I can say this, the 2nd OD to 2nd or whatever is pretty annoying with the throttle required to get it going, but I think I can manage since there arent many hills.

 

Put some 4.10's in it

 

well yeah but then I would have just taken away what I've added.

 

This is true since you did this for mileage and not power.

 

Well yes, but even if I did a 3.92, if i could afford gears id do it but I have to do front and back so im not touching them.

 

The great thing about this mod, is it's easily undoable if it turns out to not make any more sense. Enjoy your gained MPG. Please report the real world gains you observe.

 

Im already getting a 2-3 MPG increase.