Should I get a Diesel

[star_deceiver]

The 5.7 and 6.4 will engine brake automatically. It senses you're going down hill, as soon as you tap the brakes it drops a gear or two and cuts fuel. All automatic, nothing you can do to stop this.

The 3.6 will do this too.

But far and away, this was always my favourite engine brake!

 

[Tulecreeper]

The 3.6 will do this too.

But far and away, this was always my favourite engine brake!View attachment 527440

Agreed, I've driven nothing but manual transmissions for the past 35 years and I have a left thigh like Popeye's arm. I decided I'm tired of that so just got an automatic this time. Not that I really had much choice, manual transmissions being much harder to come by these days.

 

[18CrewDually]

Manual is not even an option beyond 2018.

 

[ramffml]

The 3.6 will do this too.

But far and away, this was always my favourite engine brake!

Very cool that they brought that to the 3.6 as well. I love it when they give you truck features in a truck regardless of which engine you're using.

I wonder about the stick shift though, in my truck it cuts fuel while also dropping a gear, did your previous trucks cut the the fuel too when you manually downshifted while going down a hill? I don't know how important that fuel stuff plays into this, just that I think I can feel when the fuel cuts in and out (which is separately from the downshift itself); first it downshifts, then it revs up and then all of a sudden it seems to "grab" a bit more? And then if you're slowing down it reaches a point where the brake stops braking pretty quickly even though the gear doesn't change.

I could be way out to lunch of course.

 

[18CrewDually]

Very cool that they brought that to the 3.6 as well. I love it when they give you truck features in a truck regardless of which engine you're using.

I wonder about the stick shift though, in my truck it cuts fuel while also dropping a gear, did your previous trucks cut the the fuel too when you manually downshifted while going down a hill? I don't know how important that fuel stuff plays into this, just that I think I can feel when the fuel cuts in and out (which is separately from the downshift itself); first it downshifts, then it revs up and then all of a sudden it seems to "grab" a bit more? And then if you're slowing down it reaches a point where the brake stops braking pretty quickly even though the gear doesn't change.

I could be way out to lunch of course.

I think the "grab" and the release you're feeling is torque converter lock-up.

 

[tron67j]

Tron, you got it backwards. For a given load, an engine turning higher rpm is using less torque at the higher rpm. In other words, power = torque times rpm.

When you use a gas engine to tow, going to higher gear ratio gives you higher engine rpm and your tow capacity goes up. One look at truck towing charts shows this.

What you sacrifice to do that is consuming more gasoline and faster engine wear to pull that load.

Which is why diesels are used with lower gear ratios - they have higher torque at lower rpm. But the rest of the drivetrain has to be able to take that higher torque at lower rpm - transmision, u-joints, drive shaft, etc. Diesels use less fuel and wear, but cost more to purchase, because their cylinder pressures are so much higher than spark engines.

My point may have not been clear. The higher gears will require more revolutions of the engine to achieve the same speed, so the engine will get more wear and tear over the same distance. While higher gears are a bonus for towing, achieving maximum torque and hp earlier, it is a killer for mpg and in a gas engine vehicle it is heading to maximum life expectancy earlier.

I agree, towing heavy or in extreme conditions will warrant a diesel and if going that route one should opt for at least a 3500 to avoid the 1k payload penalty that essentially renders a 2500 only capable of towing high 1500 loads.

 

[NewEnglander]

Joe,

As you can see, I am a junior member. Having experience with MOPAR trucks, and cars, I would certainly advocate for switching to a diesel. The Cummins diesel is the best diesel out there imo, as it is a dedicated platform, however i would skip over the 2500 and get a one ton for a multiplicity of reason, unless you are really attached to lux amenities, or a smooth ride. Even if you don't "need' a diesel, I favor it having driven, and worked using both. I'm having some problems with my one ton, but I favor it over the Rebel I used.

 

[NewEnglander]

My point may have not been clear. The higher gears will require more revolutions of the engine to achieve the same speed, so the engine will get more wear and tear over the same distance. While higher gears are a bonus for towing, achieving maximum torque and hp earlier, it is a killer for mpg and in a gas engine vehicle it is heading to maximum life expectancy earlier.

I agree, towing heavy or in extreme conditions will warrant a diesel and if going that route one should opt for at least a 3500 to avoid the 1k payload penalty that essentially renders a 2500 only capable of towing high 1500 loads.

Very clear, interesting observation on life expectancy, thx

 

[Choupique]

higher gears will require more revolutions of the engine to achieve the same speed,

At less load, lower cylinder pressure, lower temps, higher flow rates, etc.

The simplest way to estimate engine life is fuel burn. It's going to last X gallons before its worn out. Deeper ratios will generally get better fuel mileage towing that the shallow ratios do. Shallow ratios return better unloaded economy.

Torque is what wears stuff out, and less RPMs requires more torque to do the same work. It's best for everything involved to let em spin up. Deeper ratios should be far more common than they are in pickup trucks.

 

[HEMIMANN]

Torque and rpm wear out engines - both. Time rate of work (torque) also matters.

What's more important is that the engine be purpose-built for the application - i.e., low rpm high torque or high rpm low torque.

 

[star_deceiver]

I wonder about the stick shift though, in my truck it cuts fuel while also dropping a gear, did your previous trucks cut the the fuel too when you manually downshifted while going down a hill? I don't know how important that fuel stuff plays into this, just that I think I can feel when the fuel cuts in and out (which is separately from the downshift itself); first it downshifts, then it revs up and then all of a sudden it seems to "grab" a bit more? And then if you're slowing down it reaches a point where the brake stops braking pretty quickly even though the gear doesn't change.

I could be way out to lunch of course.

I doubt the ‘16 Cummins w/G56 cut fuel. The DPF would cool down too much. It more than likely post injected fuel to keep the after system stupid hot.

The 845re with the 3.6 seems to drop 1 or 2 gears depending on how far I push the brake pedal but doesn’t take the engine over 3000rpm as I recall. Putting cruise control on it will drop more gears to try and hold its speed so long as I don’t touch the brake.

In T/H it will drop more gears and sometimes bring it to 4000rpm. For a small engine, it works fairly well.

I still miss the exhaust brake and stick shift. I don’t miss the regular cab, dump truck dually ride, or changing fuel filters in the winter.

 

[Cmz2800]

Yup. No questions asked... get the diesel. I have had my truck regen at 50-60 mph multiple times and never had an issue. Just be diligent and take it on the hwy for 15-20 min at least once a week if you can. Even then, if you are getting to 50 mph for a decent amount of time, I bet it regens just fine.

They regen while you drive between 50-60 mph?

 

[2003F350]

They regen while you drive between 50-60 mph?

Yes. It isn't the 'active' regen that tells you to keep driving, but if you scroll to the DPF status screen it will say 'automatic regen in process.' Get it every few weeks driving back and forth to work at 55 mph, approximately a 45 minute drive. If it starts to regen partway through the drive, it will usually start back up immediately when I start the truck again, and finishes before my trip is over.

 

[Tulecreeper]

They regen while you drive between 50-60 mph?

Yes. It isn't the 'active' regen that tells you to keep driving, but if you scroll to the DPF status screen it will say 'automatic regen in process.' Get it every few weeks driving back and forth to work at 55 mph, approximately a 45 minute drive. If it starts to regen partway through the drive, it will usually start back up immediately when I start the truck again, and finishes before my trip is over.

Then it's a good thing I never got a diesel. I live rural and I don't get my truck over about 45 MPH more than maybe 3 or 4 times a month.

 

[Units]

Yes. It isn't the 'active' regen that tells you to keep driving, but if you scroll to the DPF status screen it will say 'automatic regen in process.' Get it every few weeks driving back and forth to work at 55 mph, approximately a 45 minute drive. If it starts to regen partway through the drive, it will usually start back up immediately when I start the truck again, and finishes before my trip is over.

I usually get the automatic regen on about the same frequency as you, usually when the dpf status is anywhere between 45-50%. When it does that I just pass up my exit to work and cruise down the highway, flip back around and it’s usually done by then. I drive 30 miles to work mostly highway one way. I don’t want to ever have an issue with a full dpf filter because the exhaust got cool and the regen cycle never finishes completely.

 

[jejb]

They regen while you drive between 50-60 mph?

I don't know. I had an 18 2500 CTD and have a 22 2500 CTD. I'm sure they've done regens, but I never knew about it or noticed it. No regen messages, even when watching the DPF gauge.

 

[2003F350]

I don't know. I had an 18 2500 CTD and have a 22 2500 CTD. I'm sure they've done regens, but I never knew about it or noticed it. No regen messages, even when watching the DPF gauge.

If you have the DPF gauge up it should occasionally switch to saying 'Automatic Regen In Process.'

But where you WILL notice it is in your fuel mileage and your boost. On my typical drive to work my instantaneous mileage reads anywhere from 25-30 on flat ground, and my boost gauge is at zero. When I am in an Automatic Regen, my mileage in the same spots drops to 17-18, and I'm running anywhere from 1-2 lbs of boost.

 

[Cmz2800]

If you have the DPF gauge up it should occasionally switch to saying 'Automatic Regen In Process.'

But where you WILL notice it is in your fuel mileage and your boost. On my typical drive to work my instantaneous mileage reads anywhere from 25-30 on flat ground, and my boost gauge is at zero. When I am in an Automatic Regen, my mileage in the same spots drops to 17-18, and I'm running anywhere from 1-2 lbs of boost.

Are you going to delete the regen system?

 

[2003F350]

Are you going to delete the regen system?

Not until my warranty is up. If something happens before then, well, I guess Ram can pay for it.

 

[jejb]

If you have the DPF gauge up it should occasionally switch to saying 'Automatic Regen In Process.'

So I hear. But I've never seen it. I'm pretty much done watching the DPF gauge. I watched it quite a bit on my last couple of pulls just to see if that message would come up. Nada.

But where you WILL notice it is in your fuel mileage and your boost. On my typical drive to work my instantaneous mileage reads anywhere from 25-30 on flat ground, and my boost gauge is at zero. When I am in an Automatic Regen, my mileage in the same spots drops to 17-18, and I'm running anywhere from 1-2 lbs of boost.

Again, never noticed it on either truck. Towing MPG and power is pretty consistent. Mine is not a daily driver, it's a puller for our toys.