Alright lady's and gent's, I am about to pull the trigger.....2013 JKU Rubicon 2.5 AEV lift, 285/75/17s Nitto grapplers 33.60 dia. as sitting on jeep, standard transmission(6-speed for you young guys) not a daily driver simply a toy but sometimes drive to Colorado/Utah I usually cruz at 75 I do not want to turn more than 2850 RPM on freeway but I really want 4.88s who has the same diameter tires and 4.88s? if so please give me what yur turnin at 75

Thank you so much!

 

You'll be way over that rpm. Google for a bear chart and you'll see what you will run. I had 4.88s on a 2013 standard with 37s and I didn't like the rpm at 70. Even 4.56 would be a bit much for that tire size.

 

Thanks, the chart shows it about 2850 at 70, like I said not a daily driver so maybe doable

 

2012 manual, 4.56, 37's about 2400-2500 in 6th at 70. You're going to be way over geared at 4.88. Like 3k rpm at 75 over geared.

 

Yeah, I was 2650 with 37s and 4.88 at 70.

Keep in mind that driveshafts aren't have max constant rpm. You'd definitely be above that. With those size tires, I'd go 4.10.

We have a 2014 JK with those size tires and 4.10s and it's perfect.

 

Ya I have 4.10s and it is not good i personally think stock Rubicons with manuals should have 4.56. with the stock 32s and 4.10s it is almost worthless in 4hi turning 2900 RPM at 75 wont hurt me I live in the bay area most great trails are 1 hour on flat land 2 hours in the hills then the trails

 

Why bother asking the question? Get 4.88s if that's what you want. Everyone will tell you it's too much. No idea what exactly you expect to gain from that. You have a standard transmission. Other than the first 5 mph, you have complete control over what gear you are in and what rpm you are running.

The 6th gear ratio is .797. Your driveshaft will be well over 3k rpm at 70. You will easily exceed the max constant rpm of the driveshaft. The increased driveline vibrations will add stress and wear on everything. That said, it's always cool to see pictures of JK transfer cases that cracked in half on the highway.

Light it up, man.

 

Are you coming from a sports car? Not sure what you're really expecting to get out of your jeep.

 

Agreed that you'll be over geared. I'm running 4.88 and 35s (6 speed) and I run 3k rpms at 70 (But rarely drive over 65 hanging in the slow lane)

 

Which is?? I seriously don't know, so please share. This is useful for me to know as I am currently over geared awaiting the 37" fund to fill up