My jeep hates hills at highway speeds. I'd like to help that, and spend less than $500. It's a 2015 2 door rubi auto on 35s with a K&N drop in air filter and all synthetic fluids. I have a superchips flashcal that I could upgrade to the flashpaq but I was wondering where I should focus first.

 

From your profile, you're running 3.73 gears and a D30 up front.

A gear change in the differential is what will get you the best results (without an upgrade to a V8 ).

A look at the usual gear charts for a 3.8L with Automatic and 35" tires give the following choices:

4.88 - This will still be a little bit out of the proper range for your jeep but could work and keeps you in the safe zone for a Dana 30 ring & pinion

5.13 - This is in the optimal zone for your jeep but you are getting toward the edge or outside of the safe zone for a Dana 30 ring & pinion

5.38 - This is also in the optimal zone but likely won't be great on the highway and is definitely out of the safe zone for a Dana 30 ring & pinion.

 

I think short of getting a supercharger, you might be stuck with it. I'm sure you can adjust your shift points in your auto, but I'm not sure how much that will help. My Jeep sucks on any sort of hill also, but I drive a manual so at least I can downshift.

 

What Jedg said - save up and do a re-gear; that will give you your best bang for the buck as the next step up beyond that would be supercharger or V8 swap.

I wouldn't bother doing the flashpaq, any gain would be minimal at best; and the money spent would have been better put towards gears.

 

Isn't there a chart for the 3.6L that accounts for the increased hp and the better gears in the automatic transmission?

 

Agree with everything said here. It's unfortunate, but the solution is always re-gear. A lot of folks aren't thrilled with dropping $1500 +/- s so they put up with lack of power and sub-optimal shifting. Once you finally pull the trigger you then ask yourself why you waited so long. It's night and day difference that translates directly to your happiness. Although usually necessary anyhow, programmers just don't make a noticeable difference in performance. Outside of dropping major jack on a supercharger, turbo, or engine swap, gearing is the way to go. If you plan on keeping the jeep for a few years, I'd say implement a short and aggressive savings plan and regear.

 

either go smaller tires, more gearing, supercharger, or an LS swap.

 

Hrm... I looked at his profile and it listed a 2011. I now see the 2015...

 

You're not the only one....I did the same thing. Dang, sometimes it's easy to miss the obvious. So used to pulling up profile info.

 

Assuming you want to stick with 35's, a regear makes the most sense. I would probably go 4.88's, or 5.13's if you ever want to go up to 37's.