No my O2 sensors are fine, the 4.7 has never been outstanding on gas mileage. I usually average 16 MPG. You can get 18-20 highway if you do nothing but 55 but around here the interstate gets up to 75.

 

i agree with adukart, the fuel economy difference between the 4.7 and the 5.9 is HUGE, i get 15-16 around town and 19-20 highway with my 4.7, if you can find me a stock 5.9 that comes close let me know so i can go buy it right away

 

Yeah my uncle does 80-85 mph, he has a lead foot the only reason he goes that fast is my aunt won't let him go faster lol I know my city milage has gone down about 1-2mpg since I got my truck, but that is also 20k of abuse its been through (towing, occasionally embarrassing a honda, and hunting ). I've been thinking about replacing my O2 sensors since they are original and have 160k on em.

 

I specifically wanted a 2000 SLT 4WD because it had the 4.7. It has more than enough power for me and it gets fairly decent mileage for what it is. I just wish I could get the 2nd overdrive in mine, but looks like thats not possible. A friend of mine had a 2004 Ram 1500 with the same engine and transmission with all 5 speeds used, his truck seemed noticeably less peppy than my Durango, we assumed it was the weight, but now it sounds like with the 5 speed TCM it takes stomping on it more to get it to move. I do like how mine moves so easily without having to really step on it. I guess I'll just be happy with it the way it is.

 

No no you can do it, but your gear selector wont work properly and you might get a really fast engine light. On then Off almost faster than you can notice it.

 

Sorry to bring up this old thread but moparman you should read this thread https://dodgeforum.com/forum/2nd-gen...earched-2.html they talk about the 545rfe having more clutch packs.

 

Interesting, Ill subscribe to that thread to find new things out.

 

How interesting is this?.....Can you post the part# for the Jeep tcm you're getting?
I'm gonna wait and see what the outcome is before I do anything but it might be neat idea to use and additional O/D....You mention the gear selector not working properly,what exactly does it do that isn't right?

 

I think all that happens is every gear is boxed and you may get an occasional code thrown on your dash but it flashes so fast its hard to notice it. That forum that I posted earlier in the thread (D0dg3Talk), there is a user there that did it to his 2000 4.7 and I believe he said what the results were. Its actually not a 2nd o/d but it locks up your torque converter.

 

OK,adjusted TC management,I have 3.92 so good there....What a bout the additional clutches....I bet they're there to compensate the shift point and lug before the shift.....think the tcm will wear out a thin clutch pack faster?