Gas milage sucks, and i have the 3.92's in my 04 1500 4x4. Should i change the gears to a lower ratio (i need to change the fluid anyways, 50K mi).. If so, what new ratio, what brand, and where should i get them? The way i look at it, I spin the tires every time i give it any type of gas.. the truck is powerful enough to run a lower ratio? Im not looking for performance (thats why i have a sports car in the garage), but i also dont want it to be a dog when hauling. Thanks for your opinions and input.

 

if you swap your 3.92 for something smaller. . .say a 3.55 you need to remember that you have to swap the front as well so you can still use the 4x4 function.

what kind of mileage are you getting anyway???

 

Yes, i did read that i will need to change out the front also.. and it makes more than enough sense... (possibly common sense if you think about it?) anyways, it varies alot about the speed and what is towed obviously, but in optimal speed conditions on the hiway, no load i can safely say i get 16 mpg, but usually the combined highway and city driving, i usually end up at 12-13 mpg per tank.

 

I have 3.55's in my 2005 4x4, and it has the stock 265/75R17 tires. I have a few small mods that helped my fuel econ, but I don't think you'll get much better economy for what it will cost to change the gears over. I was seeing 17+ on the highway at 75mph, and now that I have a CAI, electric fan, exhaust (Cat back) and tonneau cover; I see about 20 on the highway. I'm hoping for a small change when i install my underdrive pulley soon. Just my $.02

 

I had the 04 4.7 4x2. I was averaging 14 to 18mpg. It all depended how i drove. 70 and under 18mpg......over 70 i got below 15mpg.
Have you replaced the intake and exhaust yet???? If not, those 2 will improve your mpg.

 

motorhead- what motor? I guess i didn't say that part. Mine is the 5.7 hemi. I'd have to do some calcs, but with gears, intake and exhaust, it may be worth it... but then again maybe for all that amount of money, i could get a propane or E85 conversion? (or not.. i have no idea what that would cost)

Still looking for a brand / store to purchase from... (for research purposes at this point)