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Jeep: give us a new power plant!

stickshifter

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I still can't get over the fact that my 1978 CJ-7 had much better power to weight than the current Pentastar Gladiator, and that power came on so much earlier in the power band - where it is usable. The 3.5 NA V6 in the 3rd Gen Tacoma gets the same critique as the Pentastar, as do most other engines in the mid-size truck segment :(

2021 Gladiator with 3.6 NA V6 Pentastar: 285 hp at 6400 rpms, 260 lb/ft at 4400 rpms (Source: Jeep).
Curb weight for Rubicon: 5,050 pounds (Source: Jeep).

1978 CJ-7 with 4.2 NA I6: 200 hp at 4400 rpms, 280 lb/ft at 2200 rpms (Source: Wikipedia).
Curb weight: 2,770 pounds (Source: Automobile Catalogue).

Yeah, all the current mid-size truck engines have more hp than Jeep's 1978 I6, but that CJ-7 was a much lighter vehicle, so the power to weight was actually much better in the CJ:

2021 Gladiator Rubicon: 17.7 pounds of vehicle weight per horse power.
1978 CJ-7: 13.9 pounds of vehicle weight per horse power.

2021 Gladiator Rubicon: 19.4 pounds of vehicle weight per unit of torque.
1978 CJ-7: 9.9 pounds of vehicle weight per unit of torque.

In order to get the same power to weight ratio we had in 1978 in the CJ-7, Jeep needs to put an engine in the Gladiator Rubicon that makes 363 hp, and 510 lb/ft of torque!

Conclusion: We need a better power plant in the Gladiator, but one that is relatively affordable (let's say $3,000 over the price of the Pentastar).
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texanjeeper

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Considering the weight of the Gladiator versus the weight of a Wrangler, I think the Pentastar is a pretty dang good engine especially paired with the 8 speed auto transmission. I've got no complaints so far, it's pretty peppy and goes when I step on the gas.
 
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stickshifter

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Considering the weight of the Gladiator versus the weight of a Wrangler, I think the Pentastar is a pretty dang good engine especially paired with the 8 speed auto transmission. I've got no complaints so far, it's pretty peppy and goes when I step on the gas.
Yeah, I get that the Pentastar works well for a lot of people. But load up your truck, and then come to Colorado and drive up any dirt road that goes to a trailhead at elevation (between 8,000 - 10,000 feet). All those roads are steep, and you won't be able to shift out of first gear in a manual. Not enough torque at low rpms. I've only driven the auto on a test drive down at 5,500 feet, so I don't know how it performs driving uphill at 10,000 feet. Glad you are happy with your truck!

P.S. I live at 8,500 feet
 

Mr._Bill

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They are offering the diesel to fill the power gap, but are limited by the EPA regulations imposed upon them. They will most likely be headed down the electric and hybrid path. Bigger engines will probably be limited run and special order.
 

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ACAD_Cowboy

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Having gone for a test drive in the diesel I was not exactly impressed. Having owned other high output small displacement diesels, I was expecting more grunt off the line. Perhaps it's gearing but I wasn't feeling the rotation of the earth slow in response.

My CJ7 with the 258 was a snarling rabid animal by comparison. And yes it weighed a far bit less being stripped to the bone and having no top or doors but it also had a malaise era engine with low compression and not the best head flow. But it was still a break'em loose at the light terror. I have to whip my JK like a rented mule to have any hooligan fun and that's not exactly fun.

I suppose we could make more power via twin cams, higher compression and tweaked A/F tuning and it would perform on par with the wifemobile and wifemobile 2 (3.5L Mercedes Benz V6) but would it endure trail abuse? And to be fair, most the of the problems I have on the trail are solved with more gear not more throttle except for a very small and very specific situation and it's not more throttle I need but more ground speed entering the moment.
 
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stickshifter

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They are offering the diesel to fill the power gap, but are limited by the EPA regulations imposed upon them. They will most likely be headed down the electric and hybrid path. Bigger engines will probably be limited run and special order.
Doesn't have to be bigger to be better. In 2019 FCA secured a patent for a new 3.0 liter turbocharged Inline 6, which has been given the nickname "Tornado" by the folks at FCA/Stellantis. Inline engines are better balanced than V-oriented engines, and when turbocharged, make excellent power. A forced induction 3.0 liter I-6 gas engine will make much better horse power, and almost as much torque as the 3.0 ecodiesel - without DEF and other associated emissions crap that have negatively impacted reliability of the diesel platform. The Tornado was rumored to be replacing the 5.7 Hemi. See, for example:

https://www.motor1.com/news/516432/jeep-grand-cherokee-tornado-engine/
 

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stickshifter

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I'd still take any JT over any CJ7.
As a primary vehicle - absolutely! But that wasn't really my point. My point was the enormous difference in power to weight ratio between a modern Jeep and one that is 43 years old. I was surprised; aren't you?

For my end use, the 3.6 doesn't have enough low-end torque, and the 3.0 Ecodiesel worries me. The third generation of the Ecodiesel is still very new, and is not yet proven. Winter lasts six months where I live, and for three of those months it is between -20 and -30 degrees F at night - which is about 35 degrees colder than the temperature at which DEF freezes (DEF freezes at 11 or 12 degrees F). There are multiple reports of DEF pumps failing to clear DEF fluid from the system at engine shutoff, resulting in frozen lines and thrown codes, or of DEF heater systems failing. The nearest dealer is 70 miles away, and 3,000 feet lower, and my truck is my daily driver. As summer progresses, there are also reports of the Ecodiesel overheating while towing up hill in hot weather.

For example, two references from this forum:

DEF pump problems:
https://www.jeepgladiatorforum.com/...see-dealer-warning-message.38613/#post-628156

Diesel Overheating:
https://www.jeepgladiatorforum.com/...latform-wish-there-was-a-return-policy.46233/

I am glad you are satisfied with your truck - happy Jeeping!
 
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Chance575

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So two complaints and that makes the diesel a bad option ? How many complain about how everything works and it does what it is supposed to do. You never hear from the ones who have no problems and love it. But then again I don’t troll around for stuff either
 

Willys2Gladiator

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I love the Penastar V6. Loads more peppy than my 4cyl in my 52 Willy's pickup......
No complaints here. It's not a race car and it doesn't have high Horse power. I knew this when I ordered it and I love it for what it is. Just like I did with my old 52.
 

AggieJeep

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I have taken my 2012 JKUR through the San Juan area in Colorado several times. That 3.6 has just a few less HP than the JT version but is very close. Even with the 5 speed auto and loaded with people and gear, I have NO complaints about that drivetrain. I never once thought insufficient.

I do get your point about the simple math about power/weight. There is more that must be considered these days.

I would take more if it were available just because this is America and used to always making things better. Wanting more is natural here. I must say I truly don’t need it myself.
 
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