I've been searching for days and can't figure out whether I can consider a sport with 3.73, or need a Rubi with 4.10 gearing in the 2012. Obviously, the auto Rubi with stock 3.73 gears can handle 32's, cause that's what it comes with. Also, it seems clear that the 4.10 gears can handle 35's no problem. Here's the thing: I'd like to run 315/70r17 BFG Ko's, or Nitto Trail Grapplers 305/70r17, or Toyo Mt's 295/70r17. Will any of these work for me if I get auto with 3.73?

The simple solution is the Rubi with auto and 4.10 gears. But I am new to wheeling and will start slow, so I think the sport is plenty for now. Plus it's my DD (18 mile canyon commute on the Pacific Coast). Plus--this is big--my budget will let me lift (OME 2.5 or Mopar 2), buy wheels (AEV Pintlers) and tires NOW if I get the sport. Otherwise I'm looking at about a year stock with the Rubi.

Any advice?

 

Depends long term imo. If you don't want to go bigger, go with the Rubi... save time getting the better axles, gears, and lockers. Its what I did. I know I wasn't going bigger than 35s so it had everything already there... Next tax check is lift and tires for me.

 

Remember if you plan to wheel at all the rubi comes with a much lower transfer case & lockers.... Adding these after market is possible yes but expensive.

The sport is a good DD but the rubi is a good DD and much better off road stock. If wheeling is part of your plan I'd spring for the rubicon.

 

Thanks, guys--I appreciate the advice. It seems like it makes sense to get the Rubi and bide my time. With regards to gearing, any insight on how big I can go with tires on 3.73? I believe that this is stock for the automatic Rubi.

 

Last I was aware 4.10's were standard on all rubicons unless they changed for 2012????

 

You can run them all... Its just whether you plan to ever go bigger or if you can deal with it being sluggish... If you want to run 35's get the rubi cause then you will have the lockers and a dana 44 in the front which can handle them better.

 

I can't tell any loss in performance with my Rubi when I added 305/65R17 BFG MT km2s. They measure 32.25" mounted and a tick under 33" when not mounted. I probably should have gone 315/70R17 and run a true 33". But, not really having a performance issue is nice.

I bet if I had 3.73 gears I'd tell.

I think the issues start with 35s.

 

With the new 5-speed auto, they put 3.73 gears on it for the stock 32's. Numerically higher gears on the new transmission make this possible. Sport automatics come with 3.21's for the same reason. The manuals are the same (and same transmission) as last year. The higher (numbered) gears are available as an option. $50 on the sport, free on the Rubi.