JK Wrangler 3.8l vs 3.6l Pentastar

[mhiscox]

I just posted this information in another thread, but to repeat: I have a 7,000 pound '07 JKU converted to an EarthRoamer XV-JP with 33s and 5.13 gears. The performance was adequate from the off, but I also got a substantial improvement using a Superchip TrailDash to tune the engine to run on premium fuel. I now consider the performance quite good.

I can't pretend it wouldn't be sweeter if the camper was on the new chassis. But it's pretty easy to be content knowing that the $500 for the TrailDash and the increment for premium fuel is way smaller than the add-on for a new truck. (Besides, I once had a 8-ton Unimog camper with 120 horsepower. Everything I've driven since seems like a rocket.)

 

[MtnBubba]

Here is my rationale: I know if I trade in, I'm going to get an average price at best with little off the listed price for a 2015. That being said, I can effectively add 6 years to the life of the vehicle (2009-2015) for about $7k plus tax. That's a little less than $1200 per year of ownership with a 3.6l and better transmission. From what has been said, even if it's only a small improvement, $1200 per year seems like a good deal.

I swore I would never buy another new vehicle, but this seems to make sense.

 

[dstock]

Here is my rationale: I know if I trade in, I'm going to get an average price at best with little off the listed price for a 2015. That being said, I can effectively add 6 years to the life of the vehicle (2009-2015) for about $7k plus tax. That's a little less than $1200 per year of ownership with a 3.6l and better transmission. From what has been said, even if it's only a small improvement, $1200 per year seems like a good deal.

I swore I would never buy another new vehicle, but this seems to make sense.

Just so you know, it's not just the engine/transmission, the whole thing feels better built, quieter, and more solid overall. Even the seats are more comfortable!

 

[kojackJKU]

Weren't you trying to buy a new JK250 AEV not too long ago? You definitely seemed stoked on the newer model then. I get it that some people will never see the perspective of others which is fine, but there is a subjective and objective difference between the two and in virtually all ways the newer one is superior to the old one. It's a lot like how Jeep guys were up in arms when their beloved inline 4.0 (I owned several Jeeps with the 4.0 and it was a decent mill) was replaced in the JK, and for years everyone is comparing the 4.0 with the 3.8. Now people are comparing the 3.8 with the 3.6 and will be comparing the 3.6 with whatever is next. If you're happy with the 3.8 that's great, but to say the 3.6 isn't much better is flat out wrong. My 3.6 with 4.10 gears, auto, and 315/70/17 Duratracs drives better than all the stock 3.8s I've ever driven and gets better mpg.

I actually was because I wanted to pick up a full aev rig. But they will not import into Canada. So that axed the deal. I am just saying I have been driving both and theres not THAT much difference....

 

[Dan Grec]

:sombrero: You have a 2009/w 22k miles and the life time warranty !

This times one million.

It's already paid for, and it can't break!

I say pocket that extra money, take however much time that buys you off work and go and have some adventures in that Jeep you already have.

If you succumb to "the latest and greatest" you'll forever do that, and you'll never have any money to hit the road and adventure.

If I were forever looking at the latest, I would have never taken my ~7 year old TJ Alaska->Argentina, and I wouldn't be setting out in my ~8 year old JKU around Africa, simply because I'd have to go to work to pay off anything newer, instead of spending that money on adventures.

-Dan

 

[GetOutThere]

Drive what you've got. Love what you've got. I love the Pentastar, 5 speed, and new interior. It is awesome, but it is NOT "must upgrade from the old model" awesome.

If your Jeep isn't doing it for you, you probably bought the wrong vehicle, not the wrong engine.

 

[azxr]

If you have the money do the upgrade.

I went from a 2009 JKUR to a 2015 JKUR and it really is a different vehicle. The engine and tranny combo in the 2015 work well together. I am running 315 Duratracs with the 4.10s on the 2015 and it is a so much more drivable to me than the 2009 with the stock tires. Also as mentioned the interior is much nicer and quieter.

 

[dstock]

If you have the money do the upgrade.

I went from a 2009 JKUR to a 2015 JKUR and it really is a different vehicle. The engine and tranny combo in the 2015 work well together. I am running 315 Duratracs with the 4.10s on the 2015 and it is a so much more drivable to me than the 2009 with the stock tires. Also as mentioned the interior is much nicer and quieter.

This is good to hear as I am thinking of going from 285 Duratracs to the 315's, and I have the same setup as you.

 

[Jeep or Tacoma]

I had the same questions and after configuring and figuring everything out and just about to pull the trigger I had put new rubber on the beast it has 118,000 miles on it . I took it to my service manager and he says to me
" you are crazy to sell it with the lifetime warranty, Chrsler will be fixing your jeep forever for free" That convinced me right there, so as good as the 2015 are and cool as it is to build it again and aigret as it would be to have heated leather seats. I decided to stick with my old beast. by the way the only things better on the 15 are the engine and transmission, the axles are the sam as is the rest of the running gear I believe and a life time warranty form chrysler is and I found it on their website 99 years ****** yeah 99 years!!!!!!

 

[Jeep or Tacoma]

running 316 70 17

the tires I put on are the kelly springfield safari 315 70 17 i have stock 410 gears and it is chevy Jku for me it is totally liveable.. I angst over gearing and new jeep and power and I am fine with mine as it is.

 

[dstock]

I had the same questions and after configuring and figuring everything out and just about to pull the trigger I had put new rubber on the beast it has 118,000 miles on it . I took it to my service manager and he says to me
" you are crazy to sell it with the lifetime warranty, Chrsler will be fixing your jeep forever for free" That convinced me right there, so as good as the 2015 are and cool as it is to build it again and aigret as it would be to have heated leather seats. I decided to stick with my old beast. by the way the only things better on the 15 are the engine and transmission, the axles are the sam as is the rest of the running gear I believe and a life time warranty form chrysler is and I found it on their website 99 years ****** yeah 99 years!!!!!!

I have the lifetime on my 2013 as well :sombrero:

 

[BBailey]

Own both, a 2009 JKUR with 35" Nitto's and 4.10's and a 2012 JKUR with 37" Toyo's and 3.73's (so the 2012 is running presently with a meaningful gearing disadvantage versus the 2009). Both auto's. There is absolutely no comparison between the two, the 2012 is better in every single way. Better gas milage. Better acceleration. Holds gear on the interstate better (the 2009 works extremely hard to hold 75 mph and has zero ability to accelerate and pass at that speed). Has far more comfortable seats (both are leather and the 2015 seats are even better). Interior is niceron the 2012 with a far superior layout. Stereo controls on the steering wheel are superior on the 2012. There is absolutely nothing the 2009 does better than the 2012. Nothing. If you like your 3.8, that's great, I love mine as well. But that doesn't mean it does anything better than the newer models.

That said, I've had zero mechanical problems with either of them. Both are used extensively. The 2012 is my daily driver and I put a solid 30k miles/year on her, the 2009 is used primarily by my wife and she easily puts 15k per year on hers. Both are taken off-road regularly. Neither burns oil. The 2012 (topless) gets a solid 16 to 17 mpg per tank, the 2009 (hardtop) gets around 15 mph. Off-road the differences are smaller. The extra power of the 2012 is nice at times but with D44's, could easily get you into a lot of trouble (think broken axles). In most situations, there's really not much difference off road when the speeds are sub 20 mph.

 

[mhiscox]

Thanks to all those who, like Brian, have written up useful comparisons of the two models. It's very useful to share actual user infformation, and it's much appreciated.

 

[Dzine07]

Dude, I posted this same scenario a few months ago. (Check my post history title 3.8 dilemma).

In the end I picked up a new jeep. Totally. Worth. It. Do it.

Sent from my iPhone using Tapatalk

 

[orangeTJ]

DO IT!

I had a 2012. Power was awesome, and I loved the 5 speed auto with manual mode, which was a nice feature when trailer towing (for downshifting manually when going up a hill)