4.10 for your altitude, usage and tire size. Your mileage will be good too

 

4.56 and you'll be all set. 4.10s cost a lot more for the gears themselves. There is a misconception that higher numerical gears reduce fuel economy. Running at an inefficient rpm for a given setup reduces fuel economy. Going from 3.21 to 4.10 would likely improve mpg. In the end, you wont see much change in mpg going from 3.21 to 4.56.

I'd stay away from 4.88. Perfect for 37s, a little too much for 35s.

 

I meant to add that I had 35s on a 2013 JK 6sp with 3.73s. Hated it. Especially on the highway. Have to speed to keep it in 6th gear. Lots of downshifting to 5th. All that wasted fuel.

 

4:56 with 35" tires is the perfect combo.


Sent from my iPhone using Tapatalk . Rich

 

I have a 2014 JKUR with 6sp manual and 4.10 running on 35s. Thinking of moving to 4.56. Anyone made this switch with this setup?

What I am trying to fix.... 1) it takes a bit more to get started in first. 2) 6th is worthless unless it is flat., that said I can still get to about 80 mph

4.10s seem livable but.....

 

Also looking for info from anyone that went from 4.10 to 4.88 on 3.6 liter with 6 sp manual..., what is a realistic highway cruising speed for this set-up

 

Found an awesome site for gearing comparison. Pretty simple to use.... http://www.grimmjeeper.com/gears.html

 

If you open the FAQ's right at the top of this Modified Tech area, you will find some RPM charts built specifically for the JK. Just find the chart for your engine/transmission and cross-reference the gear ratio with the tire size.

 

Thx. Did some testing this weekend on the 4.10s. They are liveable.., the only think I don't like is that starting out takes more gas than before. Might be he gears ... Might be heavier tires. 6th is really not that bad .. Cruises nice. Going to continue to monitor before I drop $1500