So disappointed in this Diesel platform; wish there was a return policy.

[CrazyCooter]

All this reminds me of the Tundra pulling the space shuttle in the commercial. I guess it is all expectations and what you are using as a baseline.

I really think the Tundra space shuttle stunt was a reaction to all of the other manufacturers choosing to NOT adopt the J2807 that particular year as Toyota had. Pretty sure any modern vehicle could pull a train, space shuttle, battleship, etc. with enough gear reduction.

This is about a vehicle that is rated at 260hp, but de-rates to about 200hp when challenged and then to 40hp when expected to perform to the challenge.

I've owned trucks where I went 12K OVER the GCVWR........They didn't overheat, but they reasonably slowed down on the grades as expected.

Sponsored

 

[jsalbre]

I think this may be a good time to point out that towing ratings are not just based on the ability of the powertrain to get weight moving. Please don't tow double (or more) of the GTWR on public roads.

 

[ShadowsPapa]

Intersting that the engineers reccomended decreasing your weight by 2% for every 1000 feet in elevation. So if you’re towing at 8000 feet you should decrease your towing by 16% or down to 5040 to 5460 pounds depending on trim…all this at 45 MPH. ..

Thinner air can't absorb as much heat energy than the more dense air at lower elevations.
That may be a factor - it's air that removes the heat. Molecules have to take on the heat energy of the coolant via the radiator. Fewer molecules per cubic feet of air moving through a radiator means fewer molecules come in contact with the radiator.

Now - is my logic sound or is there a reason it's not that simple? I know there are various types of engineers here......

 

[CreepyJeepy]

Thinner air can't absorb as much heat energy than the more dense air at lower elevations.
That may be a factor - it's air that removes the heat. Molecules have to take on the heat energy of the coolant via the radiator. Fewer molecules per cubic feet of air moving through a radiator means fewer molecules come in contact with the radiator.

Now - is my logic sound or is there a reason it's not that simple? I know there are various types of engineers here......

At elevation, there is less 'air' moving through the heat exchange units at the front of the vehicle, and the vehicle does have less air to charge the cylinders with (forced induction does help here some, but efficiency is not 100%).

The issue is IMO the radiators are not sufficiently sized to contend with the heat produced from the eco-diesel under high load conditions. They likely were able to pass J2807 by using derating software techniques that provide just enough power to pass the test, by limiting the performance of the engine.

SAE J2807

Highway Gradeability

Cooling system performance

No component failures, no diagnostic codes that alert the operator to take service or driving action, no customer warnings, no fluid loss

*A derate is not called out here.


Reminds me of when apple slowed down the iphone.... They did lose that lawsuit FYI.

 

[CreepyJeepy]

So much of towing is staying in the strongest part of your torque curve. The diesel has the torque, even with the added weight it should Tow better than a gas motor IMOP.

Y’all with the 37’s and lift completely change so many dynamics of the JT whether it be the diesel or the gas. I like the looks of the 37’s and accessories like bumpers and winches lights etc. That said you need to decide which is more important and what your intentions are for your JT. If it is towing 5000+ lbs and a trailer that is 20+ feet long with poor trailer aerodynamics, maybe that lift and 37’s isn’t a good idea.

That said, this diesel is heavily restricted. I do not own a JT diesel, but I’ve owned plenty of 1 Ton Ford diesel 7.3 turbos ( I know not apples to apples). Before chipping, changing intake and exhaust (read un-restricting these) EGT’s on the ton diesel Fords would get high towing heavy loads. After these changes, no issues except for the stock transmission.

Back to the JT; I think in the near future there will be plenty of ways to un-restrict the exhaust and intake. Make sure you don’t have a winch and lights on the front bumper restricting airflow. Get better venting from real fender side vents and change the hood to something that actually helps as well.

Drive it slower, especially at higher elevation. I know we all get in the trap of wanting to go faster, but slowing down and staying in your max torque range will keep the JT happy.

The 8 speed auto in the diesel is stronger than the gas 8 speed. Using manual on steep grade and high elevation will help. Also a re-gear would help as well. Even with stock Rubicon 33’s.

I have the gas engine and I HATE my 245x75x17 tires, but when I am daily driving or towing weight, those small tires with the 4:10’s are awesome. The Jeep performs very well with stock Sport Max Tow setup.

IMOP you are going to need to just get used to slow easy driving towing these big RVs with the JT.

Dong this doesn’t make you weak, just realize it lets more people see your awesome rig as they drive by.

P.S. the big Ton trucks with lift and large tires rolling coal as fly by you, know that most are melting transmissions and turbos.

The problem is staying at peak toque results in a derate, as the engine cant contend with the heat that is produced while producing that much power over time. They use software tricks (derate) to prevent you as a user from overheating and melting down. I am thankful for those software engineers, but disappointed in the mechanical engineers and the heat exchange units.

A vehicle rated to tow 6000 lbs shouldn't derate when towing 3000 lbs under any public roadway IMO, but that's not how SAE standards work....

 

[CrazyCooter]

I think this may be a good time to point out that towing ratings are not just based on the ability of the powertrain to get weight moving. Please don't tow double (or more) of the GTWR on public roads.

If that were the case, the JT could have a rating of double or more? By your definition, one could just switch into low range and pull 20k up the hill at 1 mph and arive at a good tow rating?

Torque is the measurement of the amount of work an engine can exert, while horsepower defines how quickly that work can be delivered.......The J2807 test would be to prove actual usable horsepower since the test dictates a 40mph minimum speed up the "Davis Dam Grade" for a SRW vehicle.

Another thing I have not found yet on the J2807 test.......Does the vehicle have to be warmed up at the start of the test, or could someone drop off a fresh chilled truck with a trailer attatched roadside and start the test? Surely that would buy some more overhead?

 

[DirkG]

I haven't read all of the posts here, but the return policy is to sell it. Pre-owned JTs are ridiculous right now (as is most of the used car market).

 

[CrazyCooter]

I haven't read all of the posts here, but the return policy is to sell it. Pre-owned JTs are ridiculous right now (as is most of the used car market).

I'd actually prefer to wait for a solution since this vehicle checks off every other box for me and there isn't anything else that even remotely interests me other than to buy a JL and at least a 1/2ton pickup to replace it. I just downsized my fleet by 34 tires to reduce the burden of possessions that hardly got used, so selling the JT is not really an option for me.

 

[FutureOdin]

I'd actually prefer to wait for a solution since this vehicle checks off every other box for me and there isn't anything else that even remotely interests me other than to buy a JL and at least a 1/2ton pickup to replace it. I just downsized my fleet by 34 tires to reduce the burden of possessions that hardly got used, so selling the JT is not really an option for me.

But do you actually think there is going to be a "solution"? The solution is tow with another vehicle.

 

[CreepyJeepy]

But do you actually think there is going to be a "solution"? The solution is tow with another vehicle.

I actually think there are improvements that can be made with the radiator, oil cooler, fan, hood. The trans oil cooler actually already has an upgrade option.

 

[biodiesel]

A vehicle rated to tow 6000 lbs shouldn't derate when towing 3000 lbs under any public roadway IMO, but that's not how SAE standards work....

I'm okay with the SAE standards since not everyone will be towing in demanding conditions and terrain. Buyers need to understand the reason behind the SAE J2807 towing test. The purpose of the test is to give buyers an opportunity to compare various makes and models.

Critical thinking is being able to understand that every vehicle has limitations. If someone buys a vehicle and is unhappy with its performance, then they didn't do their research.

 

[biodiesel]

Another thing I have not found yet on the J2807 test.......Does the vehicle have to be warmed up at the start of the test, or could someone drop off a fresh chilled truck with a trailer attatched roadside and start the test? Surely that would buy some more overhead?

The SAE J2807 was mostly developed for the 1/2 ton, 3/4 ton, and 1 ton trucks. I'm not sure what modifications (if any) have been given to the midsized trucks. With that said, here's what I found,:

"To simulate some of the toughest conditions a truck and trailer combination will face, the J2807 “Highway Gradeability” tests take place on a well-known stretch of Arizona highway, the 11.4-mile-long Davis Dam Grade. If trucks are not tested on this specific stretch of steep road, they can be run in a simulation using a “climactic” wind tunnel. Ambient temperature plays a significant role in this test with a minimum temperature of 100 degrees required at the base of the grade. In addition to a hot climate outside the truck, the test requires the air conditioning system to be set at maximum cold, with outside air selected (not recirculating) and the fan running at full blower speed."

 

[CreepyJeepy]

I'm okay with the SAE standards since not everyone will be towing in demanding conditions and terrain. Buyers need to understand the reason behind the SAE J2807 towing test. The purpose of the test is to give buyers an opportunity to compare various makes and models.

Critical thinking is being able to understand that every vehicle has limitations. If someone buys a vehicle and is unhappy with its performance, then they didn't do their research.

I read for days before buying my diesel gladiator.

I did see some reports of some overheating situations, but others that stated things work great. I don't think it's fair to say I didn't do my research. I saw many posts from forum members towing things they shouldn't and it doing alright. I assumed since i was towing only 55% of the max towing rating it wouldn't be an issue....

What I should have done is towed my camper town to the dealership and told them to hook it up during a test drive.... Lesson learned.....

I've towed 6300lbs in the mountains with my tacoma 4.0. it sucked..... But it did it without a derate, or even getting hot.......

 

[biodiesel]

What I should have done is towed my camper town to the dealership and told them to hook it up during a test drive.... Lesson learned.....

Hindsight is always 20/20, but yes, you should have asked to take the Gladiator home for a few days to test drive the vehicle.

 

[Mr._Bill]

The only real solution is to increase the frontal zone size to allow for better cooling. The Jeep engineers were not allowed to change the front end, and did the best they could within the defined parameters. I think they should have reduced the stated towing capacity for the diesel model to reduce expectations and disappointment.

Sponsored