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

Trail Jeeps

Trail Jeeps

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zimm said:
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.
Click to expand...


The 3.6 loves revs and from our experience a 4.88 and 35" tires is a good match, it'll also allow you to squeak by on 37s in the future if that's where you want to go. That being said, if you do a lot of hills or stop and go you'll actually do just fine with the 5.13s. You'll appreciate the extra oomph. You may not really notice a gigantic loss in mileage vs a 4.88, but more revs means more wear on rotating parts. This isn't like the old days with the 4.0 straight 6 where you have a tiny window where the motor is happy at freeway speeds. The 3.6 is happy being wound up for long periods of time, it just comes down to a preference of power vs economy vs wear vs road noise.
 
zimm

zimm

Caught the Bug
Thanks I just pulled the trigger on 4.88's. They're ordering the parts now. If I was going 37's anytime soon, I would have done 5.13, but I plan to be on 35's for a while.
 
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