Ram 1500 diesel review

bimbert84 wrote:

wilber1 wrote:

It's not about "downshiftaphobia", it's about lower noise levels and lower fuel consumption for the 85% of driving that doesn't require high power.

So basically, during the 85% of the time we don't need high power, the EcoDiesel can produce more power. But during the 15% we do need high power, it cannot. Keep in mind that during that 85% of the time, the Hemi will not be running in a high gear turning 4500 RPMs, so it won't be burning tons of fuel, and it won't be making a bunch of noise. And all that talk about engine torque being everything becomes rather moot.

With the Hemi, most of the time it'll be humming along at low RPMs, smoothly and quietly. But when 300HP is needed, the Hemi can harness it simply by downshifting. The EcoDiesel cannot, and it's gonna slow down despite having more peak torque.

That's the beauty of having more gears: you can choose what you want the engine to do for you based on your driving needs at any given time. Need quiet and smooth? Double OD. Need medium power? 5th gear. Need high power? Drop to 3rd.

But if the engine doesn't have enough power in the first place, the need for high power simply cannot be satisfied, no matter what you do.

-- Rob

All the low end tq is where the diesel will shine. This along with 30% more energy per volume of diesel vs gas. While the hemi is struggling to get mid teens in the city, the ecodiesel will be in the 22-23 mpg area in the city. Roughly 50% better mile per gallon.

I used to haul a 7500 lb stock trailer with my '93 GM turbo diesel one ton. I believe it was rated at 220 HP and 400 lbft of torque. It handled that load just fine. Today a half ton can better handle what used to require a one ton.

If you look at jus2shy's spreadsheet, you will see that the diesel produces 43% more power than the Hemi at 1500 RPM, 41% more at 1750 RPM and 33% more at 2000 RPM. This is the normal RPM range for highway driving so that during the great majority of its highway towing, the diesel will be more able to stay in its OD ratios pulling more weight than the hemi. Also, while it can't accelerate as fast as the Hemi, you won't need to rev the snot out of to get the load moving. When it needs more power to the wheels, it has six non OD ratios to chose from to get it up the hill including a 4.7:1 first gear. It just won't get up the hill as fast as the Hemi.

The diesel has the same tow rating as the Hemi for a reason in spite of it being down on peak HP. The beauty of having more gears works for both of them.

wilber1 wrote:

It's not about "downshiftaphobia", it's about lower noise levels and lower fuel consumption for the 85% of driving that doesn't require high power.

So basically, during the 85% of the time we don't need high power, the EcoDiesel can produce more power. But during the 15% we do need high power, it cannot. Keep in mind that during that 85% of the time, the Hemi will not be running in a high gear turning 4500 RPMs, so it won't be burning tons of fuel, and it won't be making a bunch of noise. And all that talk about engine torque being everything becomes rather moot.

With the Hemi, most of the time it'll be humming along at low RPMs, smoothly and quietly. But when 300HP is needed, the Hemi can harness it simply by downshifting. The EcoDiesel cannot, and it's gonna slow down despite having more peak torque.

That's the beauty of having more gears: you can choose what you want the engine to do for you based on your driving needs at any given time. Need quiet and smooth? Double OD. Need medium power? 5th gear. Need high power? Drop to 3rd.

But if the engine doesn't have enough power in the first place, the need for high power simply cannot be satisfied, no matter what you do.

-- Rob

campigloo wrote:

I can see the advantages of gas over diesel for a small amount of towing. I wasn't clear when I didn't mention the small displacement engines. Pulling with a large displacement gasser seems totally reasonable in smaller doses.

Displacement is irrelevant, except as being one means to the end of getting more power. Turbocharging is another. My current truck has a 3.5L V6 (EcoBoost), and as a tow vehicle, it's noticeably better than my old truck which had a 5.7L V8 (Hemi). So despite having 63% more displacement, that Hemi had 20 less HP than the EcoBoost. In terms of power, though, that's pretty minor -- the real difference in towing performance is due to the transmission. With more gears to choose from, and better spacing between them, the EcoBoost can spend a lot more time in its powerband vs. my old Hemi.

The new Hemi, though, is a completely different story. With 400HP and 8 speeds in the tranny, it's a towing monster. Too bad the Ram 1500 chassis isn't up to the task.

-- Rob

bimbert84 wrote:

As I said earlier, those with downshiftaphobia will like the diesel better. Those who are content to let their automatic transmissions do what they were designed to do won't care as much. As always, it comes down to economy, longevity, and personal preference -- not peak engine torque as the article said.

It's not about "downshiftaphobia", it's about lower noise levels and lower fuel consumption for the 85% of driving that doesn't require high power.

I can see the advantages of gas over diesel for a small amount of towing. I wasn't clear when I didn't mention the small displacement engines. Pulling with a large displacement gasser seems totally reasonable in smaller doses.

campigloo wrote:

This has been a great read, but readily admitting being somewhat simple minded, I just don't see some of the advantages in having peak performance at very high rpm.

You bring up excellent points. The advantage of being able to turn higher RPMs is that you can use a lower gear, and all things being equal, lower gears put more torque to the wheels than do higher gears.

Diesel engines compensate for this by providing more torque at the crankshaft. But there are disadvantages to that. More torque means you need heavier-duty components, which means added cost and weight. On the other hand, it often means greater longevity.

campigloo wrote:

When I drive, I don't take off from a dead stop @4000 rpm.

I don't either, and this is where the diesel will excel. But in my truck, with my 4.17 1st gear, I'll be at 3500 RPM before I even cross the intersection. From there, I have all the power I need and more. With my trailer behind me, I can easily outpace the normal flow of traffic, even from a dead stop on an (upwards) incline.

I prefer gas for the simple reason that 95% of my driving is not towing. Gas engines are smoother, quieter, and cost a lot less. For towing, people make it sound like a gasser will be turning 5000 RPM all day every day. Not true at all. The vast majority of the time I'm ticking away at 2000 RPMs. On those occasions when I need additional power, it's only a downshift away, and I'd much rather downshift than have to slow down due to lack of power. Pulling away from a stop it will wind up more for sure, but that's such a small fraction of a typical towing trip it doesn't bother me in the slightest.

-- Rob

This has been a great read, but readily admitting being somewhat simple minded, I just don't see some of the advantages in having peak performance at very high rpm. When I drive, I don't take off from a dead stop @4000 rpm. When at highway speeds, it seems like the gas engines running at that high rpm for long periods of time would have to have a negative toll on them. Yes, they were designed to run at high rpm, but it just seems to me they wouldn't be able to sustain that long term. Please don't misunderstand, I don't mean this to insult the small engine gas fans, I just don't understand.

wilber1 wrote:

In the same gear, more torque at the engine means more torque at the wheels.

I wrote:

What I can't understand is why you think they'll be in the same gear.

wilber1 wrote:

They won't be in the same gear, that's the whole point. ...any time less than 230 HP is required, the diesel will be able to run in a taller gear than the Hemi.

Yes, of course, and I've not disputed this. What I've disputed is that engine torque is everything.

wilber1 wrote:

My point has always been that the RPM range where an engine produces its power is very important when it comes to how a vehicle drives. It's not only just about how much power it is capable of putting to the ground.

Sure, and I've agreed with that all along. What I disagree with is the article's statement that peak engine torque is what gets the work done, and when you said the statement was right, I disagreed with you.

So we do agree that higher engine torque allows you to run lower RPMs, and therefore a higher gear. And to that I say so what? I have an automatic transmission, and when the truck needs more power, it selects the gear for me. I don't have to do anything other than set the cruise control no matter what engine I have.

As I said earlier, those with downshiftaphobia will like the diesel better. Those who are content to let their automatic transmissions do what they were designed to do won't care as much. As always, it comes down to economy, longevity, and personal preference -- not peak engine torque as the article said.

-- Rob