Hi everyone,
I've been searching the heck out of the forums, but I was hoping to get a more specific answer form some of the guys who know this stuff way better than me. I got my 08 sport 4x4 4.0 auto 3.73geared about a month ago and I've already put 265/75/16 m/t's on it, which was a 2" diam. increase. From what I've read in the gearing posts I've found in searches, I'm wondering if Ford changed the trans gearing for the 08's. With these tires at around 70 in OD I'm just barely doing under 2100rpm, and the power sucks. on any kind of a hill on the highway, or to get any acceleration at all, it jumps right out of OD, back and forth etc. If 4.10's would put it just about where it was stock (which I thought was kinda mediocre acceleration anyhow), and still pretty low rpms overall, how radical of a jump is going to 4.56's? if I'm at 2000ish now @ 70 in OD, where would the rpms be with 4.56's? Thats actually my main question btw, because I know I would love the power lol! I'm getting a bonus check this week, and the gears right after so any help deciding is HUGELY appreciated. I know some will say 4.10's, but 3.73 to 4.10 doesn't seem worth the dough to me, and btw, I probably will go with some 33's 40k down the road when these tires are done.

HUGE THANKS FOR YOUR OPINIONS
Brett

 

I have 4.10s with 265/75-16s and I straight up smoke them suckers. i still believe 4.10 is overkill for only 32s..and I think its perfect for 33s.

 

josh 01blueedge has 37's with 4.56. I have factory edge size tires 235/70/16 and i have 4.10. Overkill yeah, but i get good gas mileage when i drive in the city

 

with 32's and 4.10's you'll have pretty good acceleration but you'll run higher rpms on the highway. I think that 4.56's will be overkill for your truck even with 33's. I'm going to be running 33's with 4.10's. I'm running 4.10's and 31's now. I might upgrade to 4.56's some time but I have a 3.0L with 160,000 on it. You should have enough power with 4.10's and 33's.

 

ya 32's with 4.56's is a bit much i would go with 4.10's and call it a day unless you plan on putting 35+ tires on it soon

 

i just got 35s, but ran 4.56 with 265/75/16 nittos for the last 9 months. i have the 3.0L and as long as your not strictly highway, i never had a problem. i ran 3000RPM at 65 and above. REAL smooth in city driving. on the highway you'll see the gas gauge move.

 

you dont need more than 4.10s or you don't need to change gears at all save your money buy a lift then put 35s on it with 4.56s later this summer

 

I'll be installing 4:56's this week with 32's. Then when I wear out my tires I'll change to 35's.

 

I drove it around quite a bit today with the OD off when I wasn't on the highway, and it really wasn't bad. My main gripe really is when its in OD on the highway, if a mediocre hill comes up it drops out of OD to maintain speed. Even on a small hill, it won't accelerate at all hardly without dropping out of OD. Just seems to be way to much of a dog on the highway. I know the gearing "is what it is", but would the money be better spent on a programmer and a K&N CA and maybe an exhaust? Could those improvements accomodate the OD better on the highway? That was actually my original plan......

thanks for your opinions guys

Brett

 

yes, get exhaust, intake, pullies, and a programmer and you'll notice it won't seem like a dog anymore.

 

I talked to ring&pinion. They cleared me up on how much a 4.10 would actually help the 32's, being the equivelant of having a 3.83 and stock tires. That works out good enough since I thought the 3.73 on stock tires was not great but acceptable. 3.73 to 4.10 is a bigger jump than I thought I guess. They reccomended a good place here in town they do business with to do it, so I've figured this out.....I'm getting 4.10's, a flowmaster 40 exhaust setup (unless there is one that sounds deeper and louder), a K&N 63series, and an Xcal2.....heck with choosin, I want it all! lol

Brett

 

im running 32's with 4.10 and im not having a troubles at all, plus i have some room to upgrade if i get 33's some day

 

x2