i have a sahara with 35's i need gears....... which is most recomended on my sahara? its an AUTO..... would 5:13's be ok on the fre way?

 

Bunch of info on this use search but I went 513s based upon advice I found here and my local install shop. 2400 RPM at 70ish, I wish it was a bit lower but the 513s put the pep back in it at all speeds/rpms and picks up about 2 mpg. It still downshifts on a slight grade @ speed so Im afraid that the 488s wouldnt be as good for highway driving even considering a lil less rpm. Overall the first and best mod for the 35s IMO. I paid 1500 installed. Good luck

 

Get the 5.13's. The auto with it's .69 OD ratio needs 5.13's. The stick with it's .84 OD can get by with 4.88's. An auto JK with 35's is a whole different vehicle with 5.13's; you stay in OD a whole lot better and the cruise is now usable.

And here is the dirty little secret; the milage will be the same as a stock Rubi and much better than 4.10's and 35's. I just completed a 250 mile trip today, going from 4600 to 10000 ft (and back), including about 30 miles of muddy or snowy road (in 4 Hi) lots of 65 mph, some 75 and as high as 80 mph and some full throttle 5500 rpm runs passing slow trucks on mountain roads and got exactly 18.0 mpg for the trip. And look at my sig - I am by no means light and carry a lot of recovery gear, tools, etc in the Tuffy drawer. All the RH stuff is 1/4".

I have never encountered anybody with an auto and 35's or 37's who regretted going with 5.13's. Most who went with 4.88 wish they had done 5.13's.

 

what about someone with a 6 speed 2 door? i want to lift mine up and put at least 35s maybe 37s. drive mostly highway with very limited off road use. would 4.88s or 5.13s be better. i somtimes drive long distances from alabama to texas.... i dont want to have the motor revving wayy high with 5.13s. but i am not sure if it would. any help would be great.

 

How does a lower gear ratio give you more mpg?

 

Go with the 5.13s. I did. Mine is a auto too with 35" tires. I'll be installing mine this weekend

 

In a word - yes. And especially so if an Unlimited or heavy due to aftermarket bumpers, winch, skids etc. With an auto and 35's or 37's 5.13 are really the way to go. Look at my sig line - it should be obvious that I'm heavy. I have not lost gas mileage from stock Rubi configuration and weight; but my performance is far superior to stock. It may seem counterintitive but I think what is going on is that the 3.8 is happier at the higher rpm (2600 on the freewaay at 75 and 2250 at 65) than it was when stock.

 

I would imagine a 2dr with 35's and a 6 speed would be just fine with 4.88's. With 37's I'd probably go with the 5.13's. I actually think an auto with 37's would be better served with 5.38's.

 

Tough choices.... 4.88 or 5.13s....
I have 35" Toyo Mud tires and I am getting better torque off the line than when it was stock 31" tires... - Im sure the 5.13's will give me more torque off the line and more power... - but at what MPG. - Sopose it depends on your use...
I dropped from 16.5" avg. MPG to 12.5" with the 4.88 and 35" tires.. But I love the way it drives.
Best of luck - Im sure either way you choose - you will be happy.... as long as you up gear after the change to the 35"'s