MikeOK

I discovered on a trip to the mountains that my '15 JK is way underpowered. When I was ascending a high mountain pass this thing would bog down so bad that little old ladies and Yugo's were passing me. My old TJ with the 4.0 inline 6 could handle these passes easily and it had noticeably more torque. My JK does get considerably better mpg, but that's the only thing that's better. My warranty is up in a year, what kind of mods have you done and are you now satisfied with it?

AnvilX14

Is it automatic or manual? What gear ratio does it have? What size tires do you have? My bet is most will tell you to regear.

MikeOK

I have the 6 speed manual. I have 33's but when I put them on my speedo only changed by 1 mph. It runs about 2100 rpm's at 60 mph, so I don't want to re-gear, it would be too low if I re-gear I think. My old TJ would smoke this thing. It's adequate for trails but not so much for the highway.

MikeOK

BTW, I have 3.73 gears.

metaldemon

I have a 2012 3.6 six speed manual. I agree that unless you spool it up, they are gutless. Nothing happens below 3000rpms. My XJ with a 4.0 five speed is so much easier to drive. You put it in fifth, and drive. The inline 6 just grunts from the bottom. Most of the time the JK sits in the garage, since I bought the 94 XJ to replace it. Thought I wanted a new vehicle - I was wrong.

AnvilX14

I have an automatic, 37s, factory 4.10 gears, and have calibrated the speedometer with an AEV Procal. If I'm climbing a hill as you have described my Jeep is definitely going to downshift from 5th to 4th and then probably even into 3rd if it's a long tall hill. So, I would suspect that in order to maintain speed, you would probably have to downshift into 5th or 4th. Is that pretty close?

MikeOK

True but even in 4th climbing at 65 mph is a stretch on some passes. On a flat highway holding 75 mph is a chore for it. I came back from CO through the OK panhandle where you can't get much flatter, and trying to hold 75 mph even drafting was about all this thing would do. Forget trying to pass.

nthinuf

There are plenty of threads to read through on Hemi/LS swaps. And if you don't want to pony up for one of those, maybe a Supercharger/Turbo would fit your needs.

MikeOK

How much does a supercharger/turbo cost? I've already sunk $35,000 in this rig and I don't know how much more the boss will let me spend.

resharp001

Outside of regearing to something lower and sacraficing some fuel economy, the options are turbo, supercharger, or engine swaps. CAI's and different tunes just aren't going to get you much of anything. Turbos/superchargers are gonna run in the $5-$8k range generally, but it seems they just bring on other issues themselves. You're kind caught between a rock and a hard spot. With your 33s, regearing to 4.10 isn't really going to be worth the financial cost, and regearing to 4.56 is probably too low for you. If you had 35s, 4.56 would probably suit you nicely. Most the time, unless you just have an unlimited budget, the guys doing engine swaps have older high mileage jeeps and the cost of an engine swap is easier to justify......new more powerful engine in a body you love vs. going out and buying a new car.

I have 5.13's with my 3.6L auto on 37" nitto trail grapplers. This weekend while in colorado my jeep climbed the passes well. I could maintain heading up the passes in 5th gear. If I had to accelerage going uphill I'd have to downshift to 4th; however, I am geared lower than most would prefer. The downside is at interstate speeds I'm cruising 3100 RPMs. It's definitely a trade off for off road performance.