R-FLEX-J

So my fuel consumption is bad to put it lightly.
37's 5:29 gears on my stock 4.0
While i feel the power is there im wondering if the 5:29s are too much gear? Im wondering if i was to go to a 4:88 ratio and added the teraflex 4:1 Tcase if that would help my MPG for highway use. Its by far not my daily driver but i am looking to improve on my MPG (cali gas prices are insane)
With the 4:88's merged to the 4:1 Tcase i would like to think that i will retain the off road capabilities.
Is there i thread that i missed in my search for advice and info? Any help would be much appreciated.
Thanks y'all
Cheers!

sandaddik2

Forget about fuel mileage with a big tire like a 37. Want good mileage go buy a prius.

And 529s? are you driving a toyota?

What is your rpm at when you are going down the road in overdrive?

R-FLEX-J

Im not overly concerned with fuel milage as a whole... just looking for a little better for getting to the trails and such. I knew i wasnt going to get "prius" milage.

I just bought the jeep about a month ago and have only driven it a handful of times between upgrades. If my memory serves me right im running at about 3k at 75...

I didnt put the 5:29s in it

And yes im a noob to JEEPS.

sandaddik2

I was poking fun because I assumed you had them installed....


Toytas run a 529 ratio in the diffs. We use a 538 as the deepest non odd ball gear ratio.

They are very close though.

Mess with the calculators on here. 3k at 75 isnt over revving though as that is pretty fast for a trail rig imo.
http://www.ringpinion.com/Calculators/Calculators.aspx

The 4:1 in the T case will help a lot in the rocks reguardless if thats what type of terrain you go wheeling in.

sandaddik2

According to Randy's ring and pinion, (I have used the calculator before and its pretty much dead on)

3rd gear is 3700 rpm which is pretty high, overdrive is 2500, that's not bad at all.
If you have a 5 speed you'd be at 2900-3k.

For something that is geared that's not bad at all. You have to decide though if you want your rig to be nice on the street or to wheel good on the trail. you have to find that happy medium as there is always a tradeoff.

kirknd4spd

What little bit you might gain by going to 4.88's and a 4:1 low range, aren't going to be worth it by the time you spend a couple thousand on gears for the axles and transfer case.
The 4:1 low would be great offroad though, I had 5.13's and a 4:1 low in a previous vehicle of mine on 31's, it would crawl over just about anything.

R-FLEX-J

Nice thanks guys! I think ill stick with my current gears. Going to do the teraflex 4:1 regardless.

stang65

that seems kinda low to me with the hp44 you have. are you a auto or manual?

xjmarc

You sure he's running a HP44 cause I've never seen 5.29s for one. 5.13s and 5.38s but not 5.29s.

stang65

isnt this his jeep? https://www.cherokeeforum.com/f67/da...s-arms-190935/
pretty sure he pry has 5.38 but I dont know. just thinking that if it was a auto that doing a shifting mod would help him control the shift points.

94XjSport94

What axles do you have? Stock axles can only be geared to 4.88....