Talon101

Well, I can say i understand your point on replacing a 2012 engine with a 93 4.0.
I still think the new jeep engine should have been made like the old one.
SOLID STEEL. DURRABLE. The new inovative design is there because they
wanted to cut cost of gas consumption. Any real jeep owner doesn't buy a jeep because it's good on gas. Period.
I love my 4.0 straight six and always will. ITS Durrable.
My thoughts,
Take care.

missmyXJ

I agree with you fully. Problem is the market has changed. Just isnt enough REAL Jeep owners to back a product line. Also blame the govt and tree huggers for pushing the emissions and MPG. Personally I would like to see a modern inline 6 going into the Wrangler line. The Fiat V6 is powerful but its just not the same low end torque. We are stuck with it though.

Tonkatruck

There is quite a bit of misinformation here but I guess everyone is entitled to their opinion. My opinion is that considering a 4.0L swap into a 2012 GC is pretty ridiculous. The 3.6L Pentastar IS NOT a Fiat powertrain whatsoever. It is 100% Chrysler and is rated one of Ward's ten best engines. Its a great powerplant.

Saying "modern inline 6" engine is almost an oxymoron. The 4L is basically a 1950s/1960s 4.2L design revamped through the years. I love it as well as I have it in my 03 TJ currenlty and have had it in practically every other Jeep made in the last 30 years whether it came factory or because I put it there (ex. 78 CJ)... But I would consider swapping in a 3.6L into a TJ before I'd consider a 4L into a 2012 GC. What is wrong with getting better performance and mileage? The 3.8L in the 07-2010 Wranglers belong in the recycling yard but the 3.6L is a totally different beast. Yes it does not have the same low end torque as the 4L but if you properly setup your Jeep with gearing (axles or tcase) this is not an issue. Unless you have personally offroaded a new GC with the Pentastar you don't really know how great it is in my opinion, and I have driven them.

I would strongly suggest not even considering a 4.0L swap into a 2012, but hell, enough money and time and its possible so if you do it I'd love to see pics.

missmyXJ

Actually the misconception is that the Pentastar is 100% Chrysler. Its is 100% Fiat input and design that based that engine line. IS it built by Chrysler? Yep. Its built by chrysler for north american market. Its technology and valve timing design is all based on Fiat design. To replace an entire V6 engine line up in N.A. cars and replace with Italian engines isnt very smart marketing. Therefore you have a Chrysler Pentastar engine built by the american/mexican people.
When I get parts for 3.6 engine internals and they say Fiat or even Magneti Marelli its a good indicator that Fiat had some significant input into the Pentastar 3.6 Like I said thats a good thing though.
Look how well the 3.8 is doing in the Jeeps. It IS 100% Chrysler. Its also using up the worlds oil supply. LOL. 2 towed in with no oil so far this week and one more looking for LOF records for her seized engine. I say thank you Fiat.
I still miss my 4.0 regardless. The big mistake was replacing it with the 3.8 , the 3.6 is a big positive.

Talon101

Il admit i posted the idea of a 93 -2012 jeep rubicon engine transfer but it
was purely speculative. I was just curious about workability.
Any how it has started some most interesting discussion if you ask me.
I also agree a trasfer case mod or trans mod could remedy torque.
Still i agree with missmyxj , Also , how much gas are you really going to save
with mds in a new jeep. Anyone know?? Note how often are you going to be shifting in
to that mode for fuel savings , I think it's a stupid waste of engineering unless your
talking really long drives or something. Also is mds automatic can it
just activate when it knows how much power you need? Anyone.

missmyXJ

MDS is all software run. Its running in the background. It does work well on the 2010 trucks and up. It will drop cylinders even around 60km/hr now. Its much more aggressive than the earlier versions. Only disadvantage is it gets a bit of exhaust drone since the exhaust is tuned for the frequency of 8 cylinders.
It can be turned off with the tow/haul button.

Tonkatruck

Not trying to be rude, but I would have to say the "misconception" may be on your part. The 3.6L Pentastar - originally called the Pheonix - is 100% Chrysler. I say this somewhat knowingly because my Chrysler facility built all of the prototypes in 2007/2008 before production in the USA and Mexico went into full swing. Neither the technology nor the valve timing design has anything to do with Fiat engineering. It was being built long before Fiat had anything to do with Chrysler (ie. January 2009).
And I would also have to disagree (hopefully) with the market having an issue of putting in Italian engine in a North American car because that is exactly what the 2013 Dodge Dart is getting along with Fiat's Multi-air valve system which will be integrated into other Chrysler engine - however NOT the 3.6L or 5.7L Hemi currently. Also on the Italian engine note, I sure think people wouldn't mind a nice Ferrari engine in their Chryslers either.

Out of curiousity, what "internal engine parts" come labelled with Fiat on them? I am not necessarily disagreeing since I am not 100% sure and don't want to speculate however it is likely only because they may be made by a Fiat subsidery like Magneti Marelli - who have been making components for Chrysler for many years. It would be like saying Ford is also Italian because they have Magneti Marelli components.... Or Chinese, Japanese, Korean, Mexican, etc....


But either way, at the end of the day my stance is that it wouldn't be a bad thing if it was a Fiat design... but... the 3.6L is not.

Oh, and to clear it up incase there was any misunderstanding - the MDS is only on Hemi's not the 3.6l Pentastar and its now called FuelSaver Technology or something like that.

missmyXJ

Not rude at all. Its actually really interesting info. Funny how the info we get at the dealer level even from the higher ups at Chrysler isnt always accurate. Not that it surprises me though. LOL. We were told from day one that the 3.6 was the result of Fiats input. After 20+ years of dealing with Chryslers ummm.... info I will take your word for it.

AS for engine parts I cant recall exactly what seals they were but we were replacing cam phasers again. Seals came with Magnetti Marelli packaging and the phasers are now coming with fiat bags in Chrysler boxes. Maybe Fiat is building the revised phasers??


I assumed the original poster was talking about the Hemi MDS but perhaps he thought the 3.6 used it?? It does work well in the newer Hemis. Im in the habit of hitting the fuel mileage average in vehicles at work. The numbers are without a doubt much better on the 2010 Hemis and up. Just had a 2008 Aspen with 8.5mpg average. OUCH. Thirsty Hemi that one. Usually they are around 12-13. Newer ones are up around 15-16 this time of year.

Talon101

Hello again,
I think i need to clarify,
which new jeeps does mds apply to?
Ultimately, does mds make a real difference in fuel economy say when
driving to work for 30 mins.
Like instead of 6 cyls use 4 or whatever. I see MDS as a limited boost
unless your doing long drives where a 4 cyl would clean house.

missmyXJ

Only the Hemi is using it. It needs it. The 3.6 doesnt need mds. Its not a slob like the Hemi. Now mind you the 3.6 I have checked in the Grand Cherokees are getting around 17mpg. Thats about the same as my 4.0 Cherokee used to get. The V6 engines just dont seem to do well in the heavy vehicles for mpg.