Ok, I have an 09 Wrangler Unlimited X and have the 373 gears in it at the moment... I have 35" tires and am trying to figure out what gears would be the best overall for a daily driver and off road mix... I would like good performance without my gas milage sucking...

One chart says 373 gears would put me in the yellow(best gas, poor preformance) and 411s would put me in the green (good gas, good performance)

The other chart which seems to be more specific for my vehicle (auto trans) says that the 373s are way on the low end and are not even color coded and that the 513 gears would put me in the green with my 35" tires.

Anyone one who can speak from experience or just has better knowledge of all this than I give me some opinions. I want good gas and good preformace, so I would want to be in the green....

I have BF Goodrich KM2's and a 4" lift.....

Thanks!

 

The first chart is for a 1:1 transmission ratio while the second chart makes provisions for OD. If you want to use the first chart, which I also believe is based on a different engine than what is in the JK, plan on turning OD off.

 

yes, the first chart I threw together is based on a 1:1 ratio (5th for standards, OD off for autos) and it is fairly preliminary provided to give you an idea where to go. The second chart if far more inclusive, and specific to the JK auot or standard. Keep in mind that a lot of the 'performance' is subjective for every person.

 

Silly question but what exactly is the benifit of OD?

So it sounds like the second chart is more suitable for the JK auto tranny....

Would you recomend 513s or 410s? I can get a rubi axle with the 410s but would have to spend more to change the gears.... would 513s be worth the extra expense?

I know it is subjective to each person but I'd like opinions

Thanks,

Ryan

 

I can't place a determination on your personal cost/value analysis, but I will say that if you have an automatic transmission, the 5.13s are going to put less wear and tear on the transmission and fluids while also giving you an efficiency boost.

 

The second chart is just about exact to what I'm running. I have 35's, 5.13 gears with auto tranny.

 

5:13's are pushing it when it comes to the D30/D44, so I've heard.

IMO, I would go 4:88's. I don't want to speed in the Jeep so I don't need the acceleration that 5:13's would give and I wouldn't want my engine running 2500 RPM all the time.

 

The consensus on this forum and others is the 5.13s for an auto, even with a D30. The rpm statement is ill conceived, as the engine will need to make less power per stroke, running more negative manifold pressure and the immediacy of power available just by opening up the throttle body blade. If you really want to put wear and tear on your drivetrain have it unlock the converter and kickdown every time you hit a grade or something as simple as an overpass on the freeway.

 

What brand gears do you all recomend?

 

one thing to think about, most tires are not what they say they are. i have 35/12.50/17 and to get my speedo right useing gps tire size was set to 33.75. so i measured them and thats what they came out to. just something to think about