2thousand5.4

Is there any current members left on here that are running 4.56s and 35s? If so what's your mileage like (I know gas saving will never make up for the the cost of regearing) I just want to make sure my milage won't go down a ton. Right now I'm getting 13.5ish or a little more with 3.55s and 285/70/17s. How's the top end with 4.56s, like when you are accelerating hard does it shift alot sooner than stock or does it feel like it runs out of gears to quickly? I think wide open my truck shifts from 1-2 at about 40 mph maybe more. I am hardly ever wide open I'm just curious. I drive a lot and I want to make sure I'm picking the "most enjoyable driving" ratio. I do drive mostly highway to school (about 13 miles on the high way one way going 65-70) 3 days a week but other than that I do all city driving. It probably works out to about 50/50 highway/city driving. Also is it OK to tow in OD with 4.56s? I don't tow anything now but in the distant future I would like to get a 72 inch wide 15-17 foot Jon boat or a tracker, so nothing to heavy really. Should I be ok towing that in OD? In 3rd at high way speed the engine is probably screaming with 4.56s, around 4k rpm right? I don't know if I will be going bigger than 35's, but the possibility is always there. Not anytime soon tho. So if any of yall have 4.56s how do you like them? Any complaints?

PerryB

I have 285/75-18's on my '05 and 4.56 gears. Those tires spec out at 34.8" diameter so thats pretty close. I like that gear ratio a lot. At 65 I'm turning just under 2100 and at 70 I'm turning 2275. At 80 its 2575 rpm.
If I was doing a lot of freeway driving I'd have gone with 4.10's, but I'm mostly rural/county roads and in the mountains pulling an ATV trailer. For me the 4.56 is great. It really makes the truck a lot livelier, especially in the hills eith the trailer. I have an Edge tuner so I have pushed my shift points (and torque conv. lock points) up a few miles per hour across the board. It also lets me calibrate my speedo perfectly. I like the 4.56's. If you're going with 35's, I'd go 4.56 without hesitation.

2thousand5.4

Awesome thank you! I have really been on the fence between 4.56 and 4.10, but have been leaning to 4.56. I live in South East Virginia so it's pretty much all flat here. The only Hills we have are over passes. I just did the math and Im right at 50/50 highway/city so 4.56s are sounding good. I think there is only like a 300 rpm difference between 4.56s and 4.10s at 70 so I figured the 4.56s are worth it. I have tunes from MPT so I'll get them to fix the speedo and shift points. How's your mileage? I was hoping to not drop much from 13.5. Thanks

2thousand5.4

I just realized I really typoed the title of this thread. Oops my bad

Jackedup00

4.56 same as I've said since day one lol.
Or 5.13 if you a boss!

w0lvez

The PCM should be reprogram when changing rear gear ratio and tires/wheels diameter to get an accurate Speedometer and Odometer reading.

Using smaller diameter wheel 15" will give you more MPG.

2thousand5.4

5.13s on 35s lol that would be like 3kish rpm at 70 lol it would have some awesome low end tho. Are you going 5.13s with your 40s?

Jackedup00

5.13s with 37s for atleast 5k miles, then 40s lol

jstockert

Another vote for 4.56 gears with 35's. You will love the setup and if I keep my foot out of it I get 12 to 13mpg city. I drive probably 20% highway.

2thousand5.4

Awesome thank you! I can't wait to get them. I don't drive crazy, but I do like to open it up every now and then. Like just passing people or quick accelerations to the speed limit, not often tho. Do you have any traction issues from a stop if you go WOT or from a roll?
I'm kinda surprised you are going with a lower gear than 5.13 for 40s. Do they even make anything lower? Lol 5.13s and 37s would put you In pretty much the exact same rpm range at 70 as I will be with 4.56s and 35s. That's not as bad as I thought it would be really. Are you still shooting to be done by the 4th? Lol