Hey all. New to the site but very much like the info exchanged. Question is I have an 08 Hemi Quad Cab Big Horn. My testosterone is boiling ..I want more power! I understand they do not change the gear ratio when they install the 20" wheels. Would the 1st. upgrade be installing a better gear ratio to get more of the power to the ground and would it also give better mpg? The remaining upgrades would be that much more rewared also no? Any comments are welcome.

 

Hey you got a nice truck there. but anyways as you said the tires don't change your gear ratio, and about changing gears, you can really only have one or the other, you can have power or you can have MPG, because if you want more torque then that means your when you take off hard yeah you will have alot of torque but when you can just going down the hwy your RPM's will be higher then what they would be stock, and the more rpms the more fuel you need, so you really can't have both

 

The real question is are you able to live with a 500 - 800 (this will vary base on gear change)rpm difference over stock in overdrive going down the road with a steeper set of gears? I'm planning for the 4.56 upgrade in front and rear of my 04. After towing my camaro half way across the the US in tow mode - i'm used to the higher rpm on the road....

 

i have been debating gears myself.... i think it would be better for me because i majority of my driving is around town... plus if you want to have that get up and go... thats a good way to get it!

 

I would appreciate this too. I do tow some, and i think that the 35's are gonna kill me. I May get 4.10's. Will they kill me on the highway, or be okay since the rubber will be bigger.

 

they will be fine with the bigger rubbers i believe... i think if i do gears im goin with 4.56's

 

Another thing to consider when regearing - I am learning new things everyday - yes your RPM's may go up - but the lower gears may take some of the strain off the engine - I have a 7000lb truck with 3.73 pushing 34's - gonna go to 35's once I level the front end. Hills kill my truck it is constantly downshifting - 4.10's would help with this I am also considering 4.56's but I am sure that would hurt my hwy mpg too much - I am not surewhat effect the 4.10'swill have on my hwy mpg but I am thinking that my mpg will be better - less downshifting, less strain on the motor - if I am wrong someone please correct me but that is how I am understanding things. So, take that into consideration when trying to figure out which gears to go to.

 

If you tow with 35" tires - you will want the 4.56 gears. That is one of the reasons we ordered an 08' PowerWagon with a manual 6-speed. We tow a 30' toyhauler camper and the transm. sucks. The 545RFE is a 3 speed with 2 overdrives. It has 4.10 gears. We had the transm. reflashed & it helped but did NOT eliminate the problem. We also put on a trans oil cooler from a one ton dually w/Hemi that is 24 row instead of the 12 row that came with it. To help control heat from all the up/down shifting.

 

I think if you had two trucks side by side one with 17" like stock and 20" you would see the smaller tires offer more get up and go and probably better mpg. The biggers tires must pay a price on mpg. Anyone out there with 17"? What kind of milage are you getting. theroetically a set of 4:66 gear sets would = having 17" tires (my math my be off a bit). Again this is all based on the factory not changing gear sets when they put 20" tires on, I may be wrong. Either way it's gonna go faster when i'm done with it.

 

So if a guy orders the 4.56 gears, and plans on having someone else install, do you also need the master kit? Or is that for rebuild? Cause that is like 350 and axle w/o intallation. Just curious