Well after 10 years and 100k miles running 35's with 3.55 gears Im going to pull the trigger for 4.56. I am getting a trailer to pull and don't want to upset the trans. It has been so good to me. I am sick of the o/d off all the time. It feels like I am driving my old Bronco which was so underpowered even with stock tires o/d was useless on any incline. I think if you treat the truck with respect you can run 35's with 3.55 gears. You can just as easially burn up a trans with stock tires if you rip around all the time. I had a friend that burned up a Lightning trans in like 30k miles. Drove like an idiot all the time.

 

Another thing too is that some tires are not true to size and could be off by as much as an inch.
I hear BFG's are a repeat offender. 35's measuring at or even below 34"s.

If I was rolling a 35" BFG, I would go with a set of 4.10's for an all around choice.

 

I just made my own post and no one is hitting it up. Came across this one so i figured I would ask. I do tow anywhere from 1 to 3 times a month. 12' dj trailer, race car, and 2 jet skis. With 35's with 4.56 and towing/4 wheeling all the time would be great, but what about it nog being an everyday acurance? I'm think 4.56 may be too much for me just normal every day, that maybe 4.30 would be better. A little more than I have but a little less jumping a whole 1.00 in gear size.

 

Ok , someone just post on my thread. Said 4.30 aren't an option. Soooo 4.56 I guess.

 

My old 35" KM2s measured 34.6" tall, and the 4.56 gears were perfect for it.

The only time I'd recommend anything lower than a 4.56 gear for 35" tires is if you have a 09+ truck with the 6 speed and never tow and only drive flat highway....it will help your mileage.

If you have a 08 or older truck with the 4 speed, you need 4.56 gears with 35s trust me. I only tow on occasion but I do drive a lot of hills and the 4.56 gears are a life saver. Even just stop and go around town, much smoother.

 

Just found my original window sticker. I have 3.73s. I'm sure some with 3.55 are jealous but no need! It pulls ok without a load but I know I still need gears with a load.

 

Anyone wanna swap 4.56 for stock??? LOL

 

Pro Comp Xtreme a/t's about only about 15K mi old and measure right at 34"

 

ok , so not the start a new thread im going to ask it here. on my 09 what is the best mileage gears for 35's. 09 f150 supercrew fx4 (3.73) i have a custom tunes and for me it downshifts way to easy( slight incline) i have a tonneau cover and never pull any thing more than a 10' trailer with a 660 grizzly on it. i can baby it and get around 17 mpg but woith cruise it gets 15mpg.

 

i'm all about optimizing my gpm....but some people try to overthink it and put way too much emphasis on it....if you're really that concerned and want better gpm, sell your truck and buy a prius

ETA: keep your foot out of the gas and let off earlier when coming to a stop...driving style has a huge impact on gpm

 

I'm about to regear real soon, looking at getting another 19ft Alumnaweld fishing boat and we have major mountain ranges here in Oregon to get to rivers. I am wanting to know those of you with 4.56 what are your rpms at or what can I expect when I'm not towing on the hwy going 75-80? I have a 4.6 and running 35s now.

 

Gear calculator:

http://www.grimmjeeper.com/gears.html

4.56's with 35's at 75 = 2300 rpm in OD.

 

Thank you. Spinning 2300 rpm @ 75 is not too bad.

 

and that's about where the lil' motor starts making torque so it'll have a better chance at maintaining speed

 

I loved having 4.56's with 35's in my old '01 4.6L. Average about 15mpg if I stayed out of it.