09 JKU + supercharger vs '12+ JKU
- Thread starter wADVr
- Start date
dstock
Explorer
Damn Jimbo, you still going on?:Wow1: That must be one tight sombrero!
I see from your posts that anyone who disagrees with you or dare call into question the attributes of the 3.8 is a "quasi-jeeper, complainer, cryer, entitled, etc." That is so not the spirit of the Jeep communities I have been a part of over the years with my modded YJ, XJ, ZJ, LJ and now 2 generations of JKUs.
It's not a big secret that re-gearing the 3.8 will help with it's deficiencies but it makes it adequate at best. The song that's old is YOU singing the praises of your 3.8 in every thread that comes up about the differences between the 3.8 and the 3.6, the latter of which you have no practical experience with whatsoever.
Is the 3.6 the end all be all of motors? Of course not. Does is seem dramatically better mated to the new auto trans then the old 3.8/auto combo? Absolutely. Does this the improvement of the 3.6 get exaggerated going directly from the 3.8 to the 3.6? Yeah that probably has a lot to do with it.
The OP is questioning the worth of trading up versus pouring more $$$ into his existing platform, it seems experience with both would be helpful. I moved almost all of my mods from my 2010 JKU to my 2013 and it was a lot of work. At the end of the day, I was glad I went the route I did despite the added expense of the new JKU. It was also a good opportunity to do some mods differently based on my experience with the 2010 JKU. I trust the OP will take all of the advice from the posters on this board and others to make his own educated decision about what will work best for his situation.
JIMBO
Expedition Leader
:sombrero: Regearing the 3.8l only makes it adequate when the gear choice was to "mild"/"conservative"/"comprovise"--the more chance you take (5.13/5.38) the more performance additions are there-
My old song will always be there everytime someone complains about the 3.8l poor performance/lousy mileage/auto disfavor-and I will correct the errors-
If you have experience with the JKUs and only think regearing makes them adequate, that tells me you regeared to 4.88/w auto and never went any further-
If you're so sick of my 3.8L support and are tired of the "old song"--PM the moderator and tell them to retire my post because of all the erroneus info I preach-
JIMBO
My old song will always be there everytime someone complains about the 3.8l poor performance/lousy mileage/auto disfavor-and I will correct the errors-
If you have experience with the JKUs and only think regearing makes them adequate, that tells me you regeared to 4.88/w auto and never went any further-
If you're so sick of my 3.8L support and are tired of the "old song"--PM the moderator and tell them to retire my post because of all the erroneus info I preach-
JIMBO
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bradfordrovers
Observer
Bottom line in my opinion, and once again just to reiterate in on of my previous posts. I'm not married to my 3.8, but as any good expedition vehicle should require, I like the simplicity and reliability of my 3.8 with a supercharger. The 3.6 is great, but it needs additional refinement, and vast improvements in reliability. I would drive anywhere, and for any length of time with my choice. If you have a 3.6, you may very well have the same confidence. I'm a Jeep tech however, and I work on both on a daily basis. Based on that, I would personally not choose a 3.6 for my Jeep, even though I have the choice anytime.
B 1000
Nothing special
This seems interesting to me. Can you give a little more detail please? Should we who made the jump to the 3.6 be concerned about something in the future years?
bradfordrovers
Observer
I dont think there is any immediate great concern on the 3.6, and Chrysler has been very good about updates. This engine is in huge circulation, and in almost every car, so I have confidence that eventually nearly all the current issues will get worked out.
B 1000
Nothing special
Gotcha. So far my engine was one of the ones that needed a new head, and was just in the shop for the power steering line thing. But both issues were handled with zero argument from Chrysler. In fact, they replaced my head just because I mentioned that I got the check engine light once. I don't know if they bothered doing a compression test at all, haha.
With that said, I still am very happy that I made the switch from the 3.8 to the 3.6 engine. The 3.8 wasn't exactly a problem free engine either. Not even rotary engines go through oil like that, haha.
bradfordrovers
Observer
Oh I know. The 3.8 is terrible at oil consumption. Lots of time a new PCV valve helps. Its interesting because in the minivan, the 3.8 never had oil consumption issues. Best of luck on your 3.6. It sure is a nice sounding engine.
wADVr
Adventurer
Bradfordrovers,
Thank you for the info on your experience with the AEV SC on your similarly equipped JKU, other than I am surprised you're still running 4.10s!! This is the type of driving that I am really looking to improve on. I come from several 4.0l XJs and CTDs that hardly know there is a mountain in the way let alone a 'hill'
Oil consumption has always been nil, until the last 5k oil change which it lost a quart, going to replace the PCV and see if that takes care of it. My thought with the SC is to really improve on the low to mid range power, also the reason I am starting my search with the AEV SC as it is designed for that range. That and I do not want to mess with a bunch of programming and other crap to get it to work correctly. I went through that phase years ago with imports and my 1st XJ. I went with the JKU to simplify life and not always be tinkering with it. This JKU has done just that, only a couple normal(for me) issues over 30k. I will welcome a few less ponies at the top end to just jump in it and hit the road.
I finally drove a new JKU again and got the same feeling i got a year ago, that it wasn't all that, but as I've said before its not a clean comparison, of course a stock JKU is going to drive better than mine with 37s. It did have a lot of top end power but ultimately that is not my concern, i am looking for low to midrange power so i can keep up with traffic without shifting down as much. I felt the stock JKU I drove still didn't have much at the 2-2500 mark. could be me, its also hard to get much of a feel for it on a short test drive in the city. This prompted me to do some more internet searching which I found some interesting dyno results of the 3.6. seems the actual at the wheel has a much different power curve than the graphs distributed early on showing the TQ curve very flat from 2k on up. Seems the actual is much closer to the 3.8 than I would have thought, but that kind of supports my seat of the pants dyno that had the same concern. still doing the research though so who knows.
Jimbo, thanks for your 3.8 support however I am still unclear what you have actually done to increase the mileage and power or just mileage? did you just regear and somehow update the shift points? do you have a SC? aftermarket intake exhaust etc? is the regearing part of the $2200 you spent to make it get 18mpg? I understand what you are saying about the engine but would like some more info. I am already geared down to 5.38s so that option is already exhausted. I do not have any power mods such as intake, exhaust, programmer etc, other than the Procal to simply adapt to the tires and gearing. I usually see little benefit from those small power adders so i have not invested in them, but if you say there is something worth looking into i will do that. It sounds like you are running 5.38s with a 33.6" tire, which is much different that trying to roll 4 37" tires down the road and up the hill. Dropping tire size down to a 35 has been an option I have been contemplating for some time and do think the gearing is better suited for a 35" tire.
RE engine swap. If this were a TJ with the same issue id be dropping a 5.3 LS in it and be done, the JK has so much more BS (computer crap) in it though that it gets much more expensive to do a proper swap. I again and not interested in tinkering with it for much time. Swapping in an LS sounds great until I think about the whole running two ECUs and stuff like that that just makes my OCD go out of control.
Thanks for all the responses, I appreciate the feedback.
Thank you for the info on your experience with the AEV SC on your similarly equipped JKU, other than I am surprised you're still running 4.10s!! This is the type of driving that I am really looking to improve on. I come from several 4.0l XJs and CTDs that hardly know there is a mountain in the way let alone a 'hill'
Oil consumption has always been nil, until the last 5k oil change which it lost a quart, going to replace the PCV and see if that takes care of it. My thought with the SC is to really improve on the low to mid range power, also the reason I am starting my search with the AEV SC as it is designed for that range. That and I do not want to mess with a bunch of programming and other crap to get it to work correctly. I went through that phase years ago with imports and my 1st XJ. I went with the JKU to simplify life and not always be tinkering with it. This JKU has done just that, only a couple normal(for me) issues over 30k. I will welcome a few less ponies at the top end to just jump in it and hit the road.
I finally drove a new JKU again and got the same feeling i got a year ago, that it wasn't all that, but as I've said before its not a clean comparison, of course a stock JKU is going to drive better than mine with 37s. It did have a lot of top end power but ultimately that is not my concern, i am looking for low to midrange power so i can keep up with traffic without shifting down as much. I felt the stock JKU I drove still didn't have much at the 2-2500 mark. could be me, its also hard to get much of a feel for it on a short test drive in the city. This prompted me to do some more internet searching which I found some interesting dyno results of the 3.6. seems the actual at the wheel has a much different power curve than the graphs distributed early on showing the TQ curve very flat from 2k on up. Seems the actual is much closer to the 3.8 than I would have thought, but that kind of supports my seat of the pants dyno that had the same concern. still doing the research though so who knows.
Jimbo, thanks for your 3.8 support however I am still unclear what you have actually done to increase the mileage and power or just mileage? did you just regear and somehow update the shift points? do you have a SC? aftermarket intake exhaust etc? is the regearing part of the $2200 you spent to make it get 18mpg? I understand what you are saying about the engine but would like some more info. I am already geared down to 5.38s so that option is already exhausted. I do not have any power mods such as intake, exhaust, programmer etc, other than the Procal to simply adapt to the tires and gearing. I usually see little benefit from those small power adders so i have not invested in them, but if you say there is something worth looking into i will do that. It sounds like you are running 5.38s with a 33.6" tire, which is much different that trying to roll 4 37" tires down the road and up the hill. Dropping tire size down to a 35 has been an option I have been contemplating for some time and do think the gearing is better suited for a 35" tire.
RE engine swap. If this were a TJ with the same issue id be dropping a 5.3 LS in it and be done, the JK has so much more BS (computer crap) in it though that it gets much more expensive to do a proper swap. I again and not interested in tinkering with it for much time. Swapping in an LS sounds great until I think about the whole running two ECUs and stuff like that that just makes my OCD go out of control.
Thanks for all the responses, I appreciate the feedback.
bradfordrovers
Observer
Thank you kindly, and your right about my gearing. I have been planning a gear change from the stock 4:10's to 4:88, but I havent been too motivated since the SC install. My crawl ratio is still pretty good, and the extra torque from the AC has no problems pushing my behemoth around.
JIMBO
Expedition Leader
:sombrero: Heh Heh, thanx T&A-
As I said earlier the main mods to my jeep, for power/performance are 5.38 gears/dual aux coolers/AEVPM for speedo&shift/33.6" tires
Now, if you goto 5.38s, then increase tire size to 35", you put the engine cruising RPM back to the bottom of the 3.8l "comfy zone" if you goto 37" you drop way below the effeciency/comfort RPM zone and you're behind the curve-
My best mileage has been at 60 mph/19.2 mpg, but thats not practical on todays freeways, however I seldom drive mine on a freeway-
When I cruise at 70 mph/2600 rpm/17.2 mpg-
If you want 37" tires/5.38 gears--you'll suffer performanc/mileage---unless you swap to Dana 60s and get into the 6.xx gearing-
I chose Hankook LT295/75x16s (33.6"), because I didn't care about mileage, I wanted performance/power(applicable) to the ground and I tow my off-road trailer-and I wanted life outta my axles/brakes/tranny-
My jeep is for camping/fishing/explore and with full skid plates/adj LCAs--there's nowhere I've had any trouble going and there is/was no reason to goto 35"/37" tires, thats when the 3.8L"really needs some mods for comfortable ops-
I hope you enjoyed our little argument, as I said the new jeeps are full of advantages/warranties/surprises and thats the way it's always been, everybody wants a NEW car-
My "old song" has been about the reliability/satisfaction from the "OLD" 3.8L, but you can't be a couch potatoe, it takes some personal dedication and a lotta guys in "MODERN" society-ain't gotit and rely on free dealer oil changes/fixem donetime--
Take the bull by the horn and fixit yourself-I have, my jeep has had 8 to 10 warranty problems and I've fixedem--nothing major engine/tranny, then I'd goto dealer-
Jeep is now close to 7 years old--it's a cherry-
I don't lie, I'm open to questions and my jeeps exactly as I claim !
Good luck
:costumed-smiley-007:wings: JIMBO
As I said earlier the main mods to my jeep, for power/performance are 5.38 gears/dual aux coolers/AEVPM for speedo&shift/33.6" tires
Now, if you goto 5.38s, then increase tire size to 35", you put the engine cruising RPM back to the bottom of the 3.8l "comfy zone" if you goto 37" you drop way below the effeciency/comfort RPM zone and you're behind the curve-
My best mileage has been at 60 mph/19.2 mpg, but thats not practical on todays freeways, however I seldom drive mine on a freeway-
When I cruise at 70 mph/2600 rpm/17.2 mpg-
If you want 37" tires/5.38 gears--you'll suffer performanc/mileage---unless you swap to Dana 60s and get into the 6.xx gearing-
I chose Hankook LT295/75x16s (33.6"), because I didn't care about mileage, I wanted performance/power(applicable) to the ground and I tow my off-road trailer-and I wanted life outta my axles/brakes/tranny-
My jeep is for camping/fishing/explore and with full skid plates/adj LCAs--there's nowhere I've had any trouble going and there is/was no reason to goto 35"/37" tires, thats when the 3.8L"really needs some mods for comfortable ops-
I hope you enjoyed our little argument, as I said the new jeeps are full of advantages/warranties/surprises and thats the way it's always been, everybody wants a NEW car-
My "old song" has been about the reliability/satisfaction from the "OLD" 3.8L, but you can't be a couch potatoe, it takes some personal dedication and a lotta guys in "MODERN" society-ain't gotit and rely on free dealer oil changes/fixem donetime--
Take the bull by the horn and fixit yourself-I have, my jeep has had 8 to 10 warranty problems and I've fixedem--nothing major engine/tranny, then I'd goto dealer-
Jeep is now close to 7 years old--it's a cherry-
I don't lie, I'm open to questions and my jeeps exactly as I claim !
Good luck
:costumed-smiley-007:wings: JIMBO
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Chris85xlt
Adventurer
Could it be from the change in oil weight? i believe the older minivans called for 10w-30 but now its all 5w-20.
I haven't driven a 3.6L wrangler yet, but im happy with my 3.8L mated to the 6spd. Average mpg is around 15 and 17 highway.
bradfordrovers
Observer
It very well could be the oil, and I have run 10W30 in mine. Honestly, my oil consumption hasn't been bad, and interestingly enough, I have had zero oil consumption issues since the install of the AEV Supercharger.