2005 here with a 4.0, 42rle, and 31" hybrid tires. Plans to go to to 33" some day. I'm new to Jeeps, and a shade tree mechanic at best. This is more to learn than anything. I've seen a lot of threads about all of these, but none that really address the pros and cons vs each other.
This post is mostly seeing if my logic is sound on my options. I'd like to make a fully loaded jeep actually able to go up a hill without downshifting to the point it is a 4500 rpm, and still slowing down. I went on a wheeling/camping trip in the Ozarks. Granted said hill was pretty steep, but still on a highway. Going 70 fully loaded and with a roof rack as well. I understand the Jeep is a brick on wheels, but starting to mill over options to get some more power out of it. I also assume there isn't a fix to getting 12 mpg fully loaded and going 70 in windy/hilly terrain.
Re-gear seems to be everyone's "cheap" go to for "getting power back". I totally agree the way theses are geared is horrible. I've also seen people say they get a 1-2 mpg increase after a re-gear. My argument for this situation is I was already at 3k rpm on said hill. While I do plan on re-gearing I don't assume it will fix an actual "lack of power". The engine was not bogged and shifted down to 2nd putting it at around 4500 and it was still losing speed. Perhaps my logic is flawed that 3k rpm in 3rd should have more acceleration than if it were 3k in 4th. If looking at just a "power" perspective. I don't doubt it will drive much better with a re-gear though I don't see it magically fixing this problem.
A super charger seems like the next cheapest/complicated thing on the list. I've seen some posts from Chris about the Magnum Powers super charger and I may message him. This seems like an actual fix to the "lack of power". Basically doubling WHP seems like a dream come true. It also appears to be something I could just bolt on myself, then have tuned. This is what I'm currently leaning to the most. It keeps the engine the same, and seems like a simi-simple bolt on process.
An engine swap seems by far the hardest and most expensive on this list. Though it would also possibly fix the horrid gas mileage. I'd prefer not to have a diesel though, and those seem like the best options for swapping. I really like the 4.0's Ease of working on, simplicity, and reliability. I also feel like a whole engine swap is going to add a lot of "grimlins" at some point to chase down.
Let me know if my logic is flawed on any of these. I'm sure everyone's experience is different as well, and everyone likes their Jeep to drive a different way. I've seen a guy on here that argues 3.73 is a good gearing for bigger tires. I'm only at 31" and I can already tell that isn't true. At least for me personally and how I want to have my Jeep to drive, and feel. That is a wonderful thing about them as a platform. You can make it into anything you want. Thanks ahead of time for all the info that hopefully comes out of this comparison.
TLDR of my though processes
Regear
Pros- "Cheap", better power band, possibly 1-2 mpg increase.
Cons- Not an actual fix to not having enough power
Super Charger
Pros- Actually addresses lack of power, relatively "easy" install, able to be upgraded for more power if wanted.
Cons- Loss of 1-2 mpg, perhaps engine heat, it costs as much as my Jeep did.
Engine Swap
Pros- Fixes power, fixes gas mileage
Cons- Expensive, complicated, I assume will have lots of grimlins to chase down, I don't want a diesel.
