4.56 gears on the way

[mudryder18]

I am in the process of getting my gears done, and wanted to know if anyone has put 4.56s in their expys? If so what size tires are you running and what kind of mpgs are you getting. Also what rpms is the engine running around 60-70mph.

 

[nvycrmn]

have you looked into 4.88's? i do not have new gears in mine yet, i am still running 3.55 with 35" tires and i get about 10mpg (needs a tune up though) and sitting at 2k rpms at about 65-ish. if i had to guess, i would imagine it would probably be close to something like that with the 4.56 and the 37's.

i know....doesnt answer your original question! hahaha

 

[mudryder18]

Yes i was debating between 4.56s and 4.88s, but talking to several friends and getting recomendations i went with 4.56s. I didnt need 4.88s since i mainly do all pavement drivng and only occasional off roading. Yea i was running my stock 3.55s with 35s for 2 1/2 yrs and then got 38.5s and had them for a year before my rear end finally gave in. That is what is prompting me to get gears now.

 

[nvycrmn]

ahaaaa. you gonna throw a selectable locker in there while you have it apart?!

 

[mudryder18]

No im just puttin in an upgraded yukon limited slip. didnt have the funds for a locker.

 

[walnuts4x4]

I had 38s and 4.88s on my old 97 F150.... look in my album... and loved it... drove it from upstate NY border near canada to south New Jersey... a lot of times and got close to 17mpg with a 4.6.... currently have 3.73 in expy but when I have cash gonna do 4.88s... I think 4.56 are better with 35s and 4.88s are better for 37+

 

[mudryder18]

Walnuts- thanks for the input, i was really considering 4.88s but i decided go with the 4.56s due to my mechanics advice and several friends. hopefully i can get 17mpg with my new gears, i would be ecstatic with 14mpg. i also have a k&n cai, straight pipe exhaust and a superchips programmer that i can put on 87 octane mode.

 

[nvycrmn]

when you get those 4.56 stuffed in there, let us know what you come up with as far as gas mileage and rpm numbers...

 

[mudryder18]

Yea i will. i guess ill have to since it seems ill be the first one on here with them.

 

[nvycrmn]

look at it this way, you are the pioneer! hahah

 

[walnuts4x4]

yeah I would love gears.... I can get 12.5mpg out of mine with the 3.73 but would like a little more especially towing my boat... just don't have the extra cash laying around...

 

[panda24619]

shut up walnuts! i get 11 on stock... kinda. haha i want an edge. just to see what she could do on mileage and power.

 

[mudryder18]

dang panda you must driver like ur in nascar or something. i was even getting 11mpg with stock 3.55 and my 38s before she broke and when the engine was running good.

 

[panda24619]

dang panda you must driver like ur in nascar or something. i was even getting 11mpg with stock 3.55 and my 38s before she broke and when the engine was running good.

I really don't. On the freeway I get in the second to left lane and set the cruise control to 65 or 70. So idk why it's that bad. I know I need a fuel filter and to clean the throttle body and maybe do some other stuff to help. Like get an edge. Haha

 

[SOLISIMO]

I was at 11.1 before my fuel filter went. Now its a 11.7 lol. I dont think the edge will really help that much either. Gears is the way to go but I was quote close to $1000 for everything (2wd) included a rebuild kit bc of the year of the truck...

btw my EL comes with 3.73's from factory and with the 33's this thing is a pig man, I wanna get like 4.30's

 

[walnuts4x4]

edge will help mpgs.. mine went from low 11s to mid 12s after install

 

[SOLISIMO]

edge will help mpgs.. mine went from low 11s to mid 12s after install

ehhh I think alot of it has to do with driving habits too. If your getting an edge for gas mileage, your automaticaly gonna be driving with a soft foot.

 

[walnuts4x4]

not really... I didn't change driving habits except maybe drive a little harder now with the better shift points and harder acceleration

 

[panda24619]

with an edge i think i would get worce mileage. i would not be able to keep out of it. haha what ever. its all good. edge is on my list just not top.

 

[mudryder18]

Yea ive got a superchip in mine, i had to run it on performance mode before i broke my rearend to compensate for the 3.55s, but now once i get my truck back i can put it on 87 octane and hopefully that will get me much better mpgs.