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Old 03-12-2019, 08:17 PM   #21
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Name: Justus
Trailer: Hymer Touring GT
Illinois
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Originally Posted by Raspy View Post
The Ram eTorque does have regenerative braking, and I'm only speculating here, but the simple physics of the system says that the braking feature will be pretty much useless for downhill braking.

This is because it only can put energy into it's 330 watt/hour lithium battery and does not have any other way to load the motor/generator for braking. The motor is only 16 HP, so the most braking affect possible is a 16 HP retarding force, and only then until the battery is fully charged. I've been curious to read what state of charge the battery is kept at so that is has some available capacity for this charging during braking, but I haven't found it.

As a comparison, just for fun, the Cummins can produce around 150 HP in retarding force while engine braking. Possibly more with higher RPM. This can go on for as long as the truck is on a downgrade without hitting any limits and having to shut off. I love the engine brake in my Cummins and it is on all the time, towing or not. For comparison, the brakes on my 3rd gen Ram/Cummins, without the brake, lasted about 90,000 miles. My 4th gen, with the brake, is nearing 150,000 miles and has about 1/2 of it's pads left. The rotors look like they are not yet fully broken in. The brake is so powerful that I turn it off on slippery mountain roads in winter to keep it from skidding.

The main design feature of the Ram eTorque system is to allow stop/start at traffic signals and stop and go traffic, with seamless re-starting. With the engine stopped and when it is time to go, you step on the throttle and get instant torque from the motor. The engine starts within 1/2 wheel revolution and takes the load from the motor. Then between 1,000 and 3,000 RPM, where the engine is below it's peak torque and accelerating, the motor adds torque to assist it. This is where they claim the 130 ft lbs of added torque, but it doesn't add it to the peak torque of the Hem, just the mid range area of it's powerband. And it doesn't pull the truck up grades because the battery is too small for that (about the physical size of a briefcase). Then, when shifting up or down, a very short duration load or assist is applied to the crankshaft to either slow the engine on an upshift, or speed it up on a downshift, to make the shifting process feel more smooth by matching engine RPM with the transmission gear.

It truly is a "mild Hybrid" that does save fuel mostly in stop and go situations. Because it's there, they were able to program in more functions, including a mild regen braking affect. But again, I don't know how they figure that in with the state of charge of the battery and the feel of the brake pedal.

I'm actually considering buying the eTorque Hemi in a Rebel. At first I thought it was an expensive gimmick, but now it looks like it will pay for itself in fuel savings.

Also, I have a Pentastar V6 in my Jeep Rubicon. It is also available in the Ram 1500. Before buying that Jeep I extensively researched the engine design, development and manufacturing process because it was a leap forward in it's design and I was curious. It runs great and is economical, but I would never buy one for a truck to tow with. I have a personal bias against the V6 design, but that doesn't matter to anyone else. But there are a couple of things about that engine that really make me uneasy. Unfortunately, it was the only engine available in the Wrangler, so I bought one.

As far as I know, the Ecodiesel does not have the option of engine braking. Too bad! That is one of the best features with my Cummins. But the Cummins is such a giant brute of a power plant that it is definitely not for everyone. I love diesels and have since I was a kid, but they are getting very complicated, their initial cost is high, the emission systems are complex and expensive, and the fuel is constantly more expensive. The fun has kind of gone out of them. Now, with advancements in gas engine designs, gas is looking better and better. Simple emissions systems, easy maintenance, lower cost to buy and maintain and mileage that is not that far behind diesels.
Interesting breakdown of the eTorque system. The battery, I believe, powers all electronics in place of the alternator, so I'd assume there's a constant small load on it. Perhaps useful for maintaining or minimizing acceleration downhill when not pulling a trailer.

In researching trucks, I've found that in the mid-size segment, diesel simply isn't worth the premium. For example, a RWD Colorado LT with the V6 starts at $30,695, tows 7,000 lbs, and gets 18/25 mpg. Upgrading to the Duramax will get you 7,700 lbs towing and 22/30 mpg, but it starts at $36,925--a $6,300 premium. As the Duramax represents a roughly 20% improvement in fuel efficiency, and diesel is roughly 20% more expensive than regular unleaded, I would never break even. Perhaps it is more efficient when towing, but 95% of my driving isn't towing.
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Old 03-12-2019, 09:15 PM   #22
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Name: John
Trailer: Black Series HQ19
Smith Valley, Nevada
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Justus,

The pure economics of the diesel option these days doesn't make much sense to me either. I really like diesels, but their magic is mostly gone, unless you are really towing a huge rig, or a farm tractor or something. You didn't mention it, but the DEF system, the cooled EGR and the DPF are maintenance issues, or will be eventually.

Plus, I would never buy anything other than a very well proven diesel. These days Chevy and Ford are rushing their designs into production and that tells me it's a risk. I simply don't trust them. The full sized Duramax is great, but I'm referring to the smaller one in the Colorado. Ford lost me years ago and I see no reason to change my mind. Hope I'm wrong though.

That is why I'm focusing on the gas powered Rams for my own amusement. BTW, the Ram eTorque has a conventional 12V battery to run the truck systems, as usual, as well as the 48 Volt eTorque lithium battery that gets charged directly by the motor/generator. There is a DC to DC converter that charges the conventional battery from the eTorque battery I don't know if the engine has a conventional starter or not, but I don't think so. Under normal cruising along, just consider the motor/generator to be a conventional alternator that charges the lithium battery, which, in turn charges the lead acid 12V battery. So, the 12V is always fully charged as usual, but the lithium may not be. Dunno. But either way, it's capacity is very limited when thinking of it as a huge energy storage bank for regeneration or for giving much real assistance to the engine. It doesn't seem reasonable that they would keep it under-charged because the truck might be in traffic one day and in the mountains the next. No predicting. The advertising mainly focusses on how much gasoline is saved in stop and go traffic. The torque numbers must be remembered as not adding to the overall torque of the Hemi, just a mild assistant while it is not at it's own full torque output. You can't add the motor torque and the Hemi's full rated torque together.

I'm looking forward to driving one soon.

I wish I could find some reliable mileage numbers for the new Hemi trucks with eTorque.

Also, the Rebel with the air suspension looks like a very nice truck for my use.

The specific reasons I'm so interested is that I have a 2014 Ram 3500 Cummins now. But it is a big rough riding truck and the mileage is not too much better than what I believe the new Hemi will do. And mine is a standard cab, and I want a quad cab.
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Old 03-16-2019, 12:27 PM   #23
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Name: John
Trailer: Oliver Legacy Elite II
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Justus, this is first time I have heard about a regenerative system in the Ram . Thank you. I will definitely check the Ram out. I just hope they have trained the mechanics to fix the things...
When I looked at the Ram Regen system, I saw quite a bit of weight for not a lot of benefit for primary duty as a tow vehicle. With it's limited battery size, it appears to be designed for starts and limited regenerative braking. Going down a long grade, it quickly charges up the battery and then would not be nearly as effective as a "Jake Brake" or for that matter a ten speed transmission in the Fords.
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Old 03-16-2019, 03:50 PM   #24
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Name: jim
Trailer: 2019 2ndG Escape21 DeJa View pulled by 2014 Dodge Ram Hemi Sport
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I have been towing for 10 years now with Dodge Ram Hemi 1500, first was a 2009, 5 sp auto, 3;55 rear end, I got 12 mpg towing or not, all the time. Traded it in on a 2014 Ram 1500 sport with 8 sp auto and 3:21. Now I get 20-22 unhitched and over the last 6000 mile trip 15.2 towing avg. The tow mode integrates with the brake and does down shift down hills and lets the transmission slow you down. Very pleased with this set up. The ETorque would not fit me as I do little city driving, most of mine on the Ram is towing.
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