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Discussion Starter #1
We're looking for a used 2011 or newer Rubicon.
And we want a 3.73 differential ratio with an automatic transmission (not the 4.10).

The problem is that I'm finding that advertised information is often inaccurate.
How does one find which rear end ratio is installed on the Rubicon?
 

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okay I'll bite.. why 3.73 over 4.11?
 

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Not an expert, but with bigger tires come more weight. It's a more favorable ratio to help the engine with the higher weight if you choose to life and increase tire size.
for bigger tires/heavier jeep you would want the lower 4.11's. more torque going to the axle to push the tires/weight of the jeep.. i could see 3.73 for a slight gain in mpg..
 

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for bigger tires/heavier jeep you would want the lower 4.11's. more torque going to the axle to push the tires/weight of the jeep.. i could see 3.73 for a slight gain in mpg..
You're right. Read it wrong. One too many bourbons in. Read it as 4.11 over 3.73
 

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Discussion Starter #11
okay I'll bite.. why 3.73 over 4.11?
You have to realize how zero we are on knowledge about the jeep.
We are trying to glean knowledge from looking at the specs for various Rubicons for sale via AutoTrader.com
Some Rubicons have a mileage rating of 17/19 (city highway) and others have 19/21 - which I think correlates to the rear axle ratio.
Yes/No??

This Rubicon will have a mundane life of a daily driver for my wife marked with moments of sheer terror in extremely remote areas.
Thus the requirement of higher mileage if possible with the competency of a Rubicon when needed.
 

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You MIGHT see 1 mpg difference, might not and that would only be on long trips on interstates. Around town you'd have a hard time noticing. The difference between 3.21's and 4.10 might be enough to notice.

The best way to get close is to learn to read the Tachometer. If you don't use OD and drive at a steady 60 mph the tach will be about 2400-2500 rpm's with 3.73's. If the engine is running faster it is probably 4.10's, slower and it has 3.21's. This assumes factory tire size.
 

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You have to realize how zero we are on knowledge about the jeep.
We are trying to glean knowledge from looking at the specs for various Rubicons for sale via AutoTrader.com
Some Rubicons have a mileage rating of 17/19 (city highway) and others have 19/21 - which I think correlates to the rear axle ratio.
Yes/No??

This Rubicon will have a mundane life of a daily driver for my wife marked with moments of sheer terror in extremely remote areas.
Thus the requirement of higher mileage if possible with the competency of a Rubicon when needed.
Mileage ratings are different because 07 thru 2011 have the 3.8 v6 and 2012+ have the newer 3.6 pentastar and auto trans
 

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Yup, most likely the different motor/trans, and for that reason I would dump the 2011, if already looking for a newer model.

If I remember correctly, in 2012 the auto jeeps came factory with 3.73, 4.10s optional, and manuals have 4.10s.

When I was looking I called a local jeep parts dept and explained the situation, and the used the vin to verify the ratio. Saved me from buying one advertised as 4.10, when it had 3.73s.
 

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Honestly, 3.73 and 4.10 are very close. Wouldn't matter to me which one it had, heck the 4.10 would be more desirable anyways.
 

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You have to realize how zero we are on knowledge about the jeep.
We are trying to glean knowledge from looking at the specs for various Rubicons for sale via AutoTrader.com
Some Rubicons have a mileage rating of 17/19 (city highway) and others have 19/21 - which I think correlates to the rear axle ratio.
Yes/No??

This Rubicon will have a mundane life of a daily driver for my wife marked with moments of sheer terror in extremely remote areas.
Thus the requirement of higher mileage if possible with the competency of a Rubicon when needed.

As noted either gear ratio will be fine.. The 4.11/4/10 will give you a bit more fun in traffic and if you want to run a bit larger tire than stock down the road will help as well turning those. the 2012+ have around 70hp more that prior models. Here is our review of a sport model we did for the forum if you want some more reading; WranglerForum.com: 2015 Wrangler JK Sport Test Drive
 
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