pjmjk

So I have a 2010 4dr 6speed 3.8 and I'm gonna be running a set of 37inch toyos and I'm in debate with myself on whether I want to run 4.88s or 5.13s. It's going to be my daily driver with mild highway use. Mostly around town and maybe 20-30 min highway runs. I've looked at the chart and both seem like good options.

Wrangler22

I have a 3.8l and just upgraded to 5.13 and couldnt be happier. I can't wait to get my 37's!

kbp810

6 speed, 3.8, 37's here as well. I went with 4.88, and they've worked out great... But if I was too do it over again I'd go with 5.13. I'd liked just a little more pull off of 1st.

pjmjk

Yea that's what I'm trying to decide I mean I'm sizing up from 3.73s so it's gonna be a hell of a difference regardless but I'm leaning more and more towards the 5.13s the more I hear just sounds like I might as well go all the way

Biginboca

I have 3.8/6Speed/37Toyos and it's great around town and offroading. On highway I limit my cruising to about 70-75 because as you get up to 80 the engine is around 3k+ rpm and it seems to high for a constant pace. You mentioned you are doing 30 mins on highway daily, if you are comfortable around 70-75mph 5.13 is great but if you want to cruise 80+ the engine is revving too high, IMO. (The 3.8 starts using a lot of oil revving that high.). I get 13.5mpg around town also.

I'm on the highway daily also but only for 2 exits, so like 5 miles, and I wouldn't change my 5.13's. Your situation may be better off 4.88. I know another guy who lives in Florida also who swapped his 5.13 for 4.88 because he was 30 mins highway everyday and felt it was too high rpm. He's happier with 4.88. It depends on your use.

pjmjk

yea i probably wouldnt go above 70-75 anyway especially the times im on the highway with the amount of traffic lucky if i even see 65

pjmjk

by the way anyone know a good gear shop in CT?

Waldo_88

I have 37's on my 6sp JKU and am still running the stock 3.73's. Yes, it is a little sluggish but there is no way I am going to spend the money to re-gear before I get new axles. I can still hit 80 on the highway at about 2,250 rpm and get around 14 mpg average. I hit the trails as much as I can and in 4L I rarely NEED anything lower...even though it would be nice. So I guess I'm suggesting that you really think about what your rig is really used for and determine if it is really beneficial to you. Happy Wheelin'