I have a 2007 2-door JK X and just recently installed 35x12.50x20 inch tires. I have the 4.10 gear ratio with a dana 44 rear and dana 30 front axles. I have read in several posts that the best way to improve performance is to install a better gear ratio, but it seems like most of the discussions revolve around rock crawling, off-roading, etc. My jeep is used as a Daily Driver and sees almost exclusive highway miles. I frequently tow a 21 foot ski boat. I do not want to upgrade all the way to 5.13 for the gas mileage sacrifice. I'm looking at probably either the 4.56 or 4.88. So in short I need a gear that will pull a decent load, offer good power, and still be able to operate at 70-80 mph. I don't necessarily need enough low end torque/power to climb anything extreme! Any input/advice will be greatly appreciated. Thanks!

 

go with 488's

 

Do you have any idea on the potential mpg difference in the 4.56 and 4.88? Most if not all driving will be done at around 70-75 mph

 

I'm curious on this issue to. Subscribed.

 

Have you towed the boat yet? Do you have an auto or a stick?

I recently changed to 5.13s thinking I would get some real boost but it got me almost back to stock, which is to say, not all that good. I'd think 4.88s would be your best bet.

 

Why don't we all just make another thread each about gears. There just isn't enough.

 

I have a rubi, so my crawl ratio with the 4:1 was already good. But out here in montana, my 4.10's really sucked on the highway.

I am running a auto with 35" tires. I just got installed 4.88 and love them. I regained all the power back that I lost when I installed the 35" tires.

So for DD, and 35" I would recommend, 4.88.

 

I vot 4.88, puts you close to stock without being overkill.

 

[QUOTE=RCJeeper;1145566]Have you towed the boat yet? Do you have an auto or a stick?

I havn't towed it yet with the new 35's but i recently had 33x11.50x16 tires and the towing was pretty pathetic. I have a manual transmission.

 

Thanks for everyones help so far! I'm getting the vibe that 4.88's are the way to go.. But just hypothetically speaking out of curiosity, when (if ever) would the 4.56's be recommended? I know they are an option but have yet to see anyone who runs them..