I would keep the gears u are getting.5.13. If u have any thought of 35's, u will want them eventually! I run 35's and it's my dd. About 50 miles a day all highway. And I have 4.10s. It's fine.

 

Are we looking at the same gear chart? I see 926 RPM between 3.73 and 5.13 with 33" tires.

 

I meant 150ish between 4.88 and 5.13

 

I think I'd stay with the 5.13's . You say you are gonna stay with 33's but I bet you wind up with 35's.

 

I have not done a gear swap on my JK but did on my old ZJ. Went from 3.73 to 4.56 with 31" tires. It was awesome! Highway mileage dropped about .5 and in town went up 1mpg.

I'd imagine the JK would respond well to 5.13 and 33s. That is the gear swap I want to do.

The 305/65R17s I have measure about 32.5 but are MUCH heavier than stock rubicon tires.

Combined with extra weight of bumper and winch and sitting 2" taller with the leveling kit makes me err towards a lower gear.

I think the chart is great, but it doesn't factor in extra weight and wind resistance.

I think this is why you see guys with 35" tires, auto tranny, going with 5.38 gears.

If you are honest, I bet your next set of tires are 35s.

 

No, you're fine.

I got 5.13 for my 2008 JKU auto with 33s and it was perfect. Much, much better hwy driver. Mileage actually went UP 1-2mpg as the engine and tranny were no longer fighting each other at hwy speeds.

Pick up the Superchips programmer to go with it.

 

I remember mine on 33s with 410 gears it was perfect I felt. Maybe a 456 would have been just perfect back then I thought. Deffenately not a 488-513

 

I am marginal with 4.10 and my 33s.

I thought it was marginal with the rubi 32s.

Of course we all have opinions. I'd go find some local jk'rs and see what they have and how it feels to you.

I figure my auto had been paired with 31" tires and 4.10 in a previous wrangler, right? So based on this a 32 should have been 4.56. With the heavier unlimited 4.88 may have been better.

I'm sure it all came down to the gov. And their test for mileage, which we all know is not accurate.

 

The key thing here is your speed and rolling hills. It takes 40% more horsepower to roll at 80mph than at 70mph on flat ground. Now throw in a 3 degree grade, and you need to nearly double the amount of power to cope with the change in elevation. Where that puts the scenario as described would be cranking at around 26-2700 rpm to provide sufficient enough power without continually unlocking the converter or kick downs.

Keep in mind the penalty for being under geared is far steeper than being over geared. The mechanism for controlling drive train power with the appropriate gear set is the throttle blade. Not enough gear and the mechanism becomes unlocking the convertor, with power loss in the fluid coupling and also kicking down to a lower which will shoot your rpms far above anything that a steeper gear set brings.

 

The chart absolutely factors in the aero drag of the JK and also 500lbs of payload.