So I'm looking at my regear options pretty hard after wheeling last weekend. I have an 08 JKU 6sp manual with 33s and 3.21s right now. Looking to upgrade to 35 or 37s and regear. The tires will get upsized next year with the tax return. My question for everybody out there is are you or have you run 5.13s with a manual trans? What size tires are you running? Do you like it or regret the ratio? How bad is it on the freeway? Thanks in advance to everybody for your time.

 

Have a friend that has a 6 sp with 513's and 37's. He wishes now he went 488's because of his freeway driving. If you look at some of the charts it appears 513's with 37's are good for autos while 488's are good with the 6 sp. The 488's will put you in a better rpm range and give you higher mpg. But if your not on the freeway much and primarily use your JK for lower speeds and off road the 513's will be more torquey.

 

5.13, 6spd, 37" km2s. Perfect. U didn't specify if u have a pentastar. I have the 3.8 and can't imagine why anyone would want less with this weak motor on 37's. U can get away with less on the PS. Many have 4.88 and are happy with 37's and the PS.

 

I've got a 08 6spd with 5.13s on 35s. Might go up to 37s and wanted the option. I like how it drives, I live in the mtns and am constantly going up big passes and changes in elevation an now I can use higher than 3rd gear

 

If you drive hi way speeds/ on the freeway a lot I would not go higher than 4.88. With 5.13, 35s and manual trans it runs about 3000 rpm to drive 70 mph.

 

I have an '07 6-speed, 5:13's, & 37's. It's just right, but mine is now mostly just a toy. On the freeway, at about 3,000 rpm' s, it does about 75 mph +/-. The max speed is probably 85, tops.

The gas mileage really sucks. I get something like 11 to 14 mpg.

Ty...

Sent from the outside bar at Stone Brewing Company

 

With the 3.8, it likes being between 2600-3000 rpm cruising on the highway. My stock rubicon turns 2900 at 70. And it will get every bit of 17.5-18.5 mph depending on the the direction the wind is blowing. It puts it on the high side of the sweet spot for cruising speed of the 3.8. I plan on running 5.13s with 35s mainly because I only drive mine to the trails and wheel. I don't take it on road trips besides to wheel.

 

whooops

 

Thanks everybody, I was really worried about driveability since this is my dd as well, but I can handle not going 85-90 on the highway if it means I get the feeling if having a v6 back again... Right now it feels more like I have a burned out metro engine in there :(