will swapping out my 4.10's for 4.56's hurt my gas mileage or improve it? I have 35's right now and have wanted to get 4.56's. What are the changes i will see with making this swap?

 

def more torque. idk about gas mileage. i have 3.55s with 35s now and im gettin about 10 lol

 

It depends. Sometimes gas mileage will go up because the gear to tire ratio is closer to stock but sometimes it goes down. If you go offroading then you need to get bigger gears. If not then you should be ok for a while.

 

I would expect to see an improvement, even on the freeway. 4.10s and 35s is under geared and is lugging it.

If you had stock tires, your mileage would surely drop.

 

that last post was confusing, dont you mean if i had stock tires my mileage would go up? and im gettin horrible gas mileage with 35's and 4.10's. under ten

 

stock tires + 4.10's = Higher highway speed RPM's= less mpg's.

35" tires + 4.10's= Engine Lugging(not enough gear to turn tires effectively)= less highway mpg's

4.56's will bring your final drive back into the "sweet spot" = better overall performance, and better highway crusing and mpg's

 

With 35's and 4.56s I think your mileage around city would go up while the mileage on the freeway might go down. I have 35's and 4.56s and I'm at 2000 RPM at 64-65 MPH, whereas on my other truck with stock tires and 3.55's I'm at 70 at 2000 RPM. So if you do a lot of highway driving above 70 I think your mileage may decrease a tad, but overall I doubt 4.10 to 4.56s will make a drastic difference in mileage.

 

I meant if you had stock tires and put in 4.56s your mileage would go down.
There's nothing wrong with 2000 RPM at 65, it should get it's best mileage there. It's currently at 1800 RPM at 65 which is too low and hurting his mileage IMO.

 

http://www.angelfire.com/fl/procrastination/rear.html
try this site out it heped me find the right gears for my ram keep in mind all 42re-47re which includes the 46re have a tall .69 overdrive

my rig with 35x12.50 i opted for 4.88 gears for full performance but i will never return to a lower tire size so keep that in mind if you may run a smaller tire occasionally
also remember older vehicles ran over 2500 rpms all day with no problems so dont be scared of reliability.
as far as fuel milage my ram now all stock 35x12.50 5.9 and 3.55 gears gets around 10 mpg so if you ask me it cant get any worse only improve if not i gained performance for sure you can count on that!!!

 

Thanks for all of the help, I will be getting 4.56 gears soon now! All of my questions/concerns have been adressed.