4.88's for a '15 auto with 35's daily driver?

zimm

Caught the Bug
I've read countless threads. Before I pull the trigger, I want to make sure 4.88's are what I should get instead of 5.13 or 4.56.

I have a 3.6 Rubicon with 4.10s
Currently running "35's" with actually measure 33.75"

It's my daily driver, my highway cruise is 72-73mph on GPS (currently at 2400-ish rpm)

I offroad and also pull a 3000 pound camper.

I want to regear to get some more jump off the line and limit the downshifting while towing.

I'd love to say I'm going with 37's, but I still have 20-30k miles of tread left on my 35's and moving to miami for a couple of years, I really don't need 37's anytime soon, but someday I'll have 'em, which will need more mods to accommodate.

According to the gear charts, there's only 150rpm difference between 4.88 and 5.13. I'm just scared to be stuck with a 3000 rpm highway cruise for the next few years- unless that's fine for the jeep.
 

DWiggles

Caught the Bug
I've read countless threads. Before I pull the trigger, I want to make sure 4.88's are what I should get instead of 5.13 or 4.56.

I have a 3.6 Rubicon with 4.10s
Currently running "35's" with actually measure 33.75"

It's my daily driver, my highway cruise is 72-73mph on GPS (currently at 2400-ish rpm)

I offroad and also pull a 3000 pound camper.

I want to regear to get some more jump off the line and limit the downshifting while towing.

I'd love to say I'm going with 37's, but I still have 20-30k miles of tread left on my 35's and moving to miami for a couple of years, I really don't need 37's anytime soon, but someday I'll have 'em, which will need more mods to accommodate.

According to the gear charts, there's only 150rpm difference between 4.88 and 5.13. I'm just scared to be stuck with a 3000 rpm highway cruise for the next few years- unless that's fine for the jeep.

I cruise at 3k in my jeep all the time (80mph) for 3-5 hrs at a time... fuel mileage sucks (15mpg) but I have no issues. 3.6L, 6 speed manual, 5.13s & 37s :yup:
 

jorgelrod

Hooked
4.88 on 35's will feel like your jeep feels right now with the stock tires. 4.56 will feel like 3.73 on stock. 5.13 might feel high on the rpm scale

I run 4.56 on 35's daily and it feels great...


Sent from my iPhone using WAYALIFE mobile app
 
Last edited:

MR.Ty

Token East Coast Guy
I've read countless threads. Before I pull the trigger, I want to make sure 4.88's are what I should get instead of 5.13 or 4.56.

I have a 3.6 Rubicon with 4.10s
Currently running "35's" with actually measure 33.75"

It's my daily driver, my highway cruise is 72-73mph on GPS (currently at 2400-ish rpm)

I offroad and also pull a 3000 pound camper.

I want to regear to get some more jump off the line and limit the downshifting while towing.

I'd love to say I'm going with 37's, but I still have 20-30k miles of tread left on my 35's and moving to miami for a couple of years, I really don't need 37's anytime soon, but someday I'll have 'em, which will need more mods to accommodate.

According to the gear charts, there's only 150rpm difference between 4.88 and 5.13. I'm just scared to be stuck with a 3000 rpm highway cruise for the next few years- unless that's fine for the jeep.

I love my 4.88s with my 35s. (Manual trans). By far my favorite modification and I have been pushing roughly 2800rpm for about a year an a half now when I am on the highway with no issues. I have not towed anything.

You could always sell your 35s and get 37s now.
 

zimm

Caught the Bug
I love my 4.88s with my 35s. (Manual trans). By far my favorite modification and I have been pushing roughly 2800rpm for about a year an a half now when I am on the highway with no issues. I have not towed anything.

You could always sell your 35s and get 37s now.

Oh you're a bad influence. Then I need reinforced C's, another inch of lift, front driveshaft. I'm good with my 315 duratracs.
 

DWiggles

Caught the Bug
I still need to decide on 4.88 vs 5.13. The shop can't order parts and set a date until I make up my mind.

as others have said, if it were me and my jeep:
35s = 4.88
37s = 5.13

:thinking: regear is expensive, so plan ahead, and go with the long term. If you DONT plan on upgrading to 37s for SEVERAL sets of 35s, the go 4.88. IF you plan on upgrading to 37s for the next set of tires, deal with the high rpms with 5.13s for a short period of time. :thumb:

while 25k sounds like a lot of miles, 75k IS a lot of miles... so be real with yourself and your goals for the jeep
 

zimm

Caught the Bug
Thanks. I'm pretty set on 4.88's. I have no "need" for 37's other then they're cool. My tires only have 10k on them.
 

benatc1

Hooked
Im running a '16 auto, 4.88s and 35s. Im happy where its at and is fine going down highway, Being i still drive everyday I wouldn't want 5.13s- until i get 37s of course. plenty of power and doesnt ride to high in rpm range in my opinion
 

DWiggles

Caught the Bug
Thanks. I'm pretty set on 4.88's. I have no "need" for 37's other then they're cool. My tires only have 10k on them.

you can always run 37s on a 4.88 gear, it will be like a stock rubicon on 3.73s. the 5.13s are the "agressive" gear for the 37s.

the ONLY thing bad Ive ever head about the 4.88s were from guys running 37s crawling with guys who geared to 5.13 on 37s. thats it. But thats JUST like coilover envy, yeah its "cool", and i would LOVE to have them... but my jeep still gets me down the trial... ya know? :crazyeyes:
 

Kyan

Member
I cruise at 3k in my jeep all the time (80mph) for 3-5 hrs at a time... fuel mileage sucks (15mpg) but I have no issues. 3.6L, 6 speed manual, 5.13s & 37s :yup:

MPG wise, changing from 3.73 to 5.13 ratio with 35", I lost about ~2.5mpg on my 3.6L, auto. I used to get ~16mpg and now getting ~13.5mpg. When Jeep was stock, I used to get ~18mpg :grayno:
 

zimm

Caught the Bug
MPG wise, changing from 3.73 to 5.13 ratio with 35", I lost about ~2.5mpg on my 3.6L, auto. I used to get ~16mpg and now getting ~13.5mpg. When Jeep was stock, I used to get ~18mpg :grayno:

Hand calculated or the trip computer? My computer says I get 14-15. Hand calculation is 12. I drive with a lead foot with lots of traffic.
 

Kyan

Member
Hand calculated or the trip computer? My computer says I get 14-15. Hand calculation is 12. I drive with a lead foot with lots of traffic.

Kind of hand calculated. I use this old app I got for my phone.
 

Kyan

Member
I know you looking for go / no-go recommendation like I was couple of months ago but it is complicated. I have no reference case except stock 3.73 and 5.13 gear ratios. If my jeep was daily driver with some off-roading once in a while, I would not go for 5.13 with 35" tires. My best recommendation would be to catch a ride in a Jeep with the similar setup as you going for.
 

Rottenbelly

New member
I daily drive my 15 with a manual trans with 5.13's and 35s. I love it.
But I live in the mtns and constantly drive from 2500 ft to over 11k ft.
So the extra rpms help alot on the hills with the cruise set. I do limit myself to 70 mph on the interstate.
My last trip was about 400 miles round trip and I still averaged 17mpg.
I plan on going to 37s soon so I should be perfect then.
If it where me.....
Lots of hills /mtns in your area... 5:13.
Fairly flat, lots of long trips and staying with 35s awhile..
4:88.
 

SPOOOBY

New member
For towing id go 5.13 on 35, if you go to 37 your still good


If your not living and having fun,your dead already
 

RjSkippy

New member
I had 4.88s installed about 2 months ago on my daily driver and love them. Running 33s and at 72 MPH I'm running about 3100 RPM with no issues. I plan to be on 35's shortly (saving pennies) but want to reinforce the C's before I go to 35's.
 

jorgelrod

Hooked
I had 4.88s installed about 2 months ago on my daily driver and love them. Running 33s and at 72 MPH I'm running about 3100 RPM with no issues. I plan to be on 35's shortly (saving pennies) but want to reinforce the C's before I go to 35's.

You should reinforce them now, 33's can still bend your C's
 
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