This time for sure: 2012 Wrangler gets Pentastar V6, 5 speed auto
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4Rescue
Expedition Leader
Question is... WHERE in the rev range are those power numbers made??? IMO making more power is useless in a truck if it's all top end. Going to a smaller displacement V6 is NOT going to help, you need a torquier motor, not more HP... Hell, the 4.0L onlt made 190hp, but it made LOTS of torque DOWN LOW where a heavy vehicle needs it. This is just further evidence that the Mopar engineers are just following like sheep instead of bucking badly advised trends in auto-making... Either that or they're TRYING to force people to swap the Hemi in to get an adaquately powered Wrangler. Cause this V6 ain't gonna be it. Oh and where's the Diesel??? All this wasted money swapping in another engine that won't fit the bill either when they could just swap in a KNOWN performer like the VM-Motori CRD... Oh wait, we N.Americans Don't WANT a diesel cause we never buy them... cause they don't offer them... Thumbs DOWN (way down) to Mopar on this one. You've failed intentionaly. Save the high win ding car motors for a sports car you don't build and give folks who want a TRUCK a real TRUCK motor cause the 3.6 isn't it...
Cheers
Dave
Cheers
Dave
Pskhaat
2005 Expedition Trophy Champion
4Rescue, I actually agree with you here. You wanna know why they put a new auto in there, is to simply allow for a quicker shift on a smaller effective (%) power band and to play the torque rise (which is barely anything) to above 5000rpms. When was the last time you approached an obstacle in the road at 5krpms?
Compare to playing the rise below 3krpm in the 4.0:
Compare to playing the rise below 3krpm in the 4.0:
I agree for the most part about the V6 issue. I think if Jeep/Fiat could design a V6 like Fords new Ecoboost, I would be ok with that. Until then we need a diesel or Hemi. (The new Ford ecoboost has more HP and torque than my Ram with the Hemi and a nice flat Torque curve, so it can be done...)
I have seen the 3.8l and the 4.0l torque and HP curves overlaid. The 3.8 actually provides as much or more torque as the 4.0 for any rpm. The 3.8 is a hell of a lot better on the highway and doesn't sound like its going to blow at 3,000rpm's like the 4.0.
I own an LJ with the 4.o and I have to tell you that it isn't as good of an engine all around as the 3.8 as far as drivability on or off road. I'd bet that if my LJ had the 3.8 instead of the 4.0 it's be a better driving Jeep on the highway, city streets, on trails and in the rocks too. The 4.0 has been romanticized since its passing as far as its performance.
The 3.6 won't improve off road performance much, imo. But it will significantly improve the highway performance when mated to the 545rfe. The biggest issue with the JKU and the auto isn't the weak engine, it the HUGE jump from the 1:1 3rd gear to the .67:1 O/D 4th. The 545rfe has the same 1:1 3rd gear, almost the same top O/D gear at an even steeper .67:1 for its 5th, but it has its 4th at .75:1 in between.
If you want to improve off road performanc and stick with the factory engine, regear to a lower gear, lower than factory even when taking larger tires into account. Added bonus is better on road performance too, manual or auto. 5.38's are available for the D44 and now also the D30.
I went Hemi and would do it again in a heartbeat, but my wife's Unlimited Rubicon just isn't that bad stock. Re-gearing to 4.88 would fix every complaint I have - but not as well as the Hemi!
As for that, with my JKU I run the VVT Hemi, 4.88's and 37's and guess what - 5.13's would be better...
As far as the lack of a diesel, I think you can blame the US Gov't on that. The ever tightening regulations make it expensive on the automakers and remove much of the attraction of diesels. Think urea injection now on larger diesels. What a f'in joke. If the JK's see a diesel in the US it will be when the EU and US emmissions regs match up, which I think is two years out. Also the US has got to stop penalizing diesel users with higher fuel taxes.
And truthfully, the market for a JK diesel might really be thin. With the oh so common soccer mom and comuter dad use that the JK's see, especially the JKU, how likely is high demand? Not very likely, imo.
Our company runs a fleet of diesel chassis cab trucks and gas vans. The sad truth is that the gas engines are much, much cheaper to run. Less maintenance - not like the days past when gas engines required frequent tuning, carb rebuilding, new points and plugs while diesels kept on going like the Energizer Bunny. Today its the opposite. More maintenance, more expensive repairs, much of any milage advantage lost to higher fuel taxes. Don't forget higher intitial purchase price either. A diesel light truck doesn't pay for itself anymore.
For a Jeep, the only advantages would be staying within CAFE standards and the torque some want at lower rpms. But again, how many really want it with the trade offs - noise, smell, maintenance, cost - and of those how many would actually pay for it.
What the JKU's really need, imo, is a smaller V8 putting out 300lbs' and 300hp as low on the tach as possible. The ~375hp and lbs' that the 5.7 VVT Hemi put out are substantially more than the JKU's need to be about perfectly powered.
JPK
I own an LJ with the 4.o and I have to tell you that it isn't as good of an engine all around as the 3.8 as far as drivability on or off road. I'd bet that if my LJ had the 3.8 instead of the 4.0 it's be a better driving Jeep on the highway, city streets, on trails and in the rocks too. The 4.0 has been romanticized since its passing as far as its performance.
The 3.6 won't improve off road performance much, imo. But it will significantly improve the highway performance when mated to the 545rfe. The biggest issue with the JKU and the auto isn't the weak engine, it the HUGE jump from the 1:1 3rd gear to the .67:1 O/D 4th. The 545rfe has the same 1:1 3rd gear, almost the same top O/D gear at an even steeper .67:1 for its 5th, but it has its 4th at .75:1 in between.
If you want to improve off road performanc and stick with the factory engine, regear to a lower gear, lower than factory even when taking larger tires into account. Added bonus is better on road performance too, manual or auto. 5.38's are available for the D44 and now also the D30.
I went Hemi and would do it again in a heartbeat, but my wife's Unlimited Rubicon just isn't that bad stock. Re-gearing to 4.88 would fix every complaint I have - but not as well as the Hemi!
As for that, with my JKU I run the VVT Hemi, 4.88's and 37's and guess what - 5.13's would be better...
As far as the lack of a diesel, I think you can blame the US Gov't on that. The ever tightening regulations make it expensive on the automakers and remove much of the attraction of diesels. Think urea injection now on larger diesels. What a f'in joke. If the JK's see a diesel in the US it will be when the EU and US emmissions regs match up, which I think is two years out. Also the US has got to stop penalizing diesel users with higher fuel taxes.
And truthfully, the market for a JK diesel might really be thin. With the oh so common soccer mom and comuter dad use that the JK's see, especially the JKU, how likely is high demand? Not very likely, imo.
Our company runs a fleet of diesel chassis cab trucks and gas vans. The sad truth is that the gas engines are much, much cheaper to run. Less maintenance - not like the days past when gas engines required frequent tuning, carb rebuilding, new points and plugs while diesels kept on going like the Energizer Bunny. Today its the opposite. More maintenance, more expensive repairs, much of any milage advantage lost to higher fuel taxes. Don't forget higher intitial purchase price either. A diesel light truck doesn't pay for itself anymore.
For a Jeep, the only advantages would be staying within CAFE standards and the torque some want at lower rpms. But again, how many really want it with the trade offs - noise, smell, maintenance, cost - and of those how many would actually pay for it.
What the JKU's really need, imo, is a smaller V8 putting out 300lbs' and 300hp as low on the tach as possible. The ~375hp and lbs' that the 5.7 VVT Hemi put out are substantially more than the JKU's need to be about perfectly powered.
JPK
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JIMBO
Expedition Leader
:sombrero: I agree with you somewhat-but
I don't agree with the "hemi" swap, at least not for my type situation-I have an '08 JKU Rubi with 33.6" Hankook Dynapros and an auto tranny (highly modified) I have 5.38 Dana (lockable) diffs and an aux cooling/monitoring system--
Off road, towing a trailer, there's nothing more I need-
On road, towing or not I have full use of Cruise control and O/D, without downshifting-I can drive like Grandma and get 19 mpg ar tow my trailer and get 16 mpg in O/D--
So, I'm sorry, I have no need for a v8 swap-or Diesel, with my NV241OR xfer case , the only limit to what rocks/hills I can climb, off-road, is purely a matter of "GUTS", cause the JKUR will gothere-and tow the trailer right behindit !!
You're right about the fed/CAFE requirements on ones initial test drive of a new jeep--Gears-Gears-Gears and I'm afraid the new "jesus" engine will be in close to the same position !!
:costumed-smiley-007:wings: JIMBO
I don't agree with the "hemi" swap, at least not for my type situation-I have an '08 JKU Rubi with 33.6" Hankook Dynapros and an auto tranny (highly modified) I have 5.38 Dana (lockable) diffs and an aux cooling/monitoring system--
Off road, towing a trailer, there's nothing more I need-
On road, towing or not I have full use of Cruise control and O/D, without downshifting-I can drive like Grandma and get 19 mpg ar tow my trailer and get 16 mpg in O/D--
So, I'm sorry, I have no need for a v8 swap-or Diesel, with my NV241OR xfer case , the only limit to what rocks/hills I can climb, off-road, is purely a matter of "GUTS", cause the JKUR will gothere-and tow the trailer right behindit !!
You're right about the fed/CAFE requirements on ones initial test drive of a new jeep--Gears-Gears-Gears and I'm afraid the new "jesus" engine will be in close to the same position !!
:costumed-smiley-007:wings: JIMBO
Pskhaat
2005 Expedition Trophy Champion
The discreet torque value at any given RPM is not nearly as important as effective differential of them and where they fall in the RPM range. It is the shape of the curve that is just as important if not more-so than the absolute numbers.
As to your second comment about 3krpm highway feel, there is simply no doubt that the 3.8 tries to address both highway and off-road manners, it probably does pretty good in each category. Few engines out there have the true qualities of both on- and off-highway, until an engine can change it's bore:stroke, intake charge, cam, fuel mappings dynamically, we ain't gonna have it both ways.
I've driven both the stock V6 and I6 in the Jeeps and (I'm not the only one) have a preference off-highway for the 4.0, it simply performs better in that environment for nearly every situation I would personally put it in. You may or may not agree.
We are in agreement with most everything.
But I think that if you had the opportunity to drive a Hemi powered JKU on and off road you would be wanting one.
JPK
More torque = more work. You can pretend its otherwise, but it isn't. The 3.8 has more torque than the 4.0 from down low all the way up. Perhaps some of the myth surrounding the 4.0 is the generally lighter, smaller Wranglers its been in, vs the JK. Or maybe its the noise it makes down low, which is missing from the 3.8. Either way, torque is work, and and 3.8 puts out more across the rpm band.
If you want examples of engines that don't suffer on road performance gaps for off road performance, or vice versa, look no further than the good ole American pushrod V8's. Once the enngine makes more than enough torque down low for a street legal Jeep while making more than enough HP up higher for a Jeep on a street you have the near perfect powerplant. A Jeep can only use so much torque off road and be still drivable on the street and can only use so much HP on the street because its a a Jeep and not a roadster...
JPK
Pskhaat
2005 Expedition Trophy Champion
You still have to have a distance multiplier in order to derive work. As torque is a factor in the work equation it would have a relationship, but not exactly work. Add time into the equation and we get power, RPMs luckily give us both.
A flat torque curve has very little torque rise and as such does not increase torque upon load, which in nice and slow, non-racing, bumpy, off-highway situations is a good thing.
Torque is only work with RPMs and as most drives I do have a natural way of causing me to slow down naturally when approaching a water crossing, or hill, or larger rock. I prefer one that will increase the torque in the same gear as the load is applied. I just like doing that in the lower half of the RPM range vs. having to keep a good rev to accomplish the same and by that time getting real close to the max power, I'm simply not racing these things, just good old regular off-highway driving.
I as low as I have driven is a 5.13 geared six speed JKU. What an improvement over stock! I think I have an inkling of what you feel, but the 5.38's be even better. An auto even better yet.
Compared to the 5.13's, even the 5.38's too, since I've run with 5.38 geared JKU's, you would find the Hemi with 4.88's and 37's or lower gears the one to lust after.
The Hemis all make more torque at 1200rpms than the V6's make at peak. No matter how low you gear the 3.8 or the forthcoming 3.6, you can't make up for that remendous difference. That available torque gives incredible control. Contrary to what one might think, its possible to overcome obstacles with less tire spin, more control, slower speed.
Of course the Hemi has its drawback, and that is cost.
JPK
The torque curves of the 4.0 and the 3.8 are nearly identical. Wish I could find that torque and HP curve overlay. There is so little difference its more than remarkable, until 3500rpms or so, then the 3.8 overcomes the 4.0..
If you think there is significant difference between an earlier Wrangler with a 4.0 and a JK Wrangler with the 3.8, its the difference between the Jeeps and not their engines. Weight, gearing, differential set up, who knows, but it isn't the engines.
BTW, whatever the second HP/Torque curve graph you previously posted, the one below the 3.6 graph, it wasn't for the 4.0 engine.
What you write above are concerns largely overcome with lower gears. Sounds like you 4.0 experience was in Jeeps with lower axle ratios.
JPK
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