I selected the 4:10 axle ratio when ordering our new Unliited Sahara. We dropped by today with our trade and our salesman was double checking with me to make sure I wanted the 4:10 over the 3:21 because he was under the impression that jeeps with the 4:10 get approximately 25% less mpg then those with the 3:21's . for the most part, this jeep will be used on road with some light towing. It will go offroad from time to time but must likely through mud and light-med trails. It will not see any serious rock crawling or anything like that. I will, however be adding a lift and 35 or 36 inch tires in the future.
so, what mileage are you all getting with the two ratios on stock wranglers?

 

i have 2dr with 4:10 getting 18mpg to 20mpg with mixed highway and town driving. stock tires.
I beleive more will comment and tell you if you are putting that big of tire on you will want a the 4:10.

 

I have a rubicon with stock tires. 17 to 21 measured with my GPS. I believe the mini van engine we have ujses more fuel when it runs in a strain. You will like the 4.10 for mileage and power.

 

the 4.10s get the same mileage as the 3.21 i WAS getting 20 on hyw and street now with the 37 who knows cant really tell with the speedo now thinking around 15

 

25% less? Man, where'd he pull that one out of? Ask him to show you where he got that number from. At least it'll help stop an urban legend from continuing...

 

Got to agree here. Mine is an unlimited with auto and 4.10s and I'm consistently getting slightly better than 18 mpg in mixed driving.

P.S. Great AVATAR KrasnayaZnamya. Old Russian uniform insignia?

 

I'm getting 20 - 22 MPG hwy. I ride the auto. I really don't know what you'll get on a stick.
65 @ 2000 RPM
80 @ 2500 RPM
On 255/75/17 tires
My best mileage is rollin' @ 75 @ 2366.66666666666 RPM
If you can, test drive the 3:21 and 4:10 on those tires and use the rates and revs as a reference.
25% ...that salesman is misinformed or is trying to cover up a screw-up on the order.
Have fun with the JK...You're gonna dig it!!!!

 

Man, 4th gear in the auto must be tall. I run closer to 3K at 80 in 6th with the 6 speed.

 

You said you're going to do light towing. If you get the Tow Package, it includes the 4.10 axle, so the point would be mute.

 

Man, there's a definite differnce in the RPMs between the auto and my manual then...in 6th at 65 I'm running closer to 2800, at 80 it's seen the other side of 3000...