Sep-21-2013 06:02 AM
Nov-03-2013 04:18 PM
wilber1 wrote:I know full well what it's doing and why. Is it your nature to be unnecessarily rude?I would call that dumbshiftaphobia. Put it in D with the cruise on, not knowing what it is doing or why.
wilber1 wrote:Only when and if I need to.Sure cruise in 7th or 6th instead of 8th with a higher noise level and fuel consumption.
wilber1 wrote:I always have the option of slowing down, in which case I don't need the extra power or the downshift. I just assumed that was obvious.Put up with frequent shifting and the wear and tear that goes along with it just so you can get up a hill faster.
wilber1 wrote:OK, so they're about the same. Whatever. The point is that if I need that power, and only if I need it, I can get it with a pretty minimal increase in RPM. That's a far cry from "revving the snot out of it" (to use your words).At 1900 RPM the Hemi isn't putting out any more power than the diesel at 1500 RPM. From the graph it looks like slightly less.
Nov-03-2013 01:30 PM
That's what I mean by downshiftaphobia. Downshifting takes zero effort from the driver, so I don't understand how it's any less relaxing. All I do is push the cruise control button and let the truck do the rest. I'll admit that frequent downshifting can be a minor annoyance, though, and in that case, I'd be content to lock out 8th and cruise in 7th. Others may not, and for them, diesels are more appealing.
Right. The closer the gears are spaced, the less noticeable the shift will be. With my 5-speed Hemi, dropping from 3rd (1.00:1) to second (1.50:1) resulted in a 50% increase in RPM, which is very noticeable. But a multi-speed transmission might result in only a 20% change. So from 1600 RPM, the next gear down would be around 1900 RPM. Lock that in place, take the 20% increase in power, and go.
Nov-03-2013 09:42 AM
Turtle n Peeps wrote:Well sure, because we're talking about 365HP vs. 240HP. But that difference won't be as dramatic for a couple reasons:Or to put it another way: The Ecoboost will eat the EcoDiesel's lunch, and it won't even be close.
Nov-03-2013 09:29 AM
wilber1 wrote:That's what I mean by downshiftaphobia. Downshifting takes zero effort from the driver, so I don't understand how it's any less relaxing. All I do is push the cruise control button and let the truck do the rest. I'll admit that frequent downshifting can be a minor annoyance, though, and in that case, I'd be content to lock out 8th and cruise in 7th. Others may not, and for them, diesels are more appealing.I keep repeating it because some people like to haul their trailer down the road at 60 MPH in eight gear instead of in seventh or even sixth. They like to do it without their truck shifting down at every little 2% rise in the highway.... If you want relaxed cruising, buy the diesel.
wilber1 wrote:Actually, that's exactly what it means, by definition. At whatever vehicle speed you choose, the one producing more power can pull more weight.Just because it doesn't get up a hill fast enough to suite you doesn't mean it can't tow as much.
wilber1 wrote:Of course they do. The whole point is the more gears you have, the less important the torque output of the engine becomes. And that's precisely because you have more options for trading off engine torque for wheel torque. This very concept is why it's wrong to say that peak engine torque is what gets the job done.Yes, multi speed transmissions make a difference but they do it for all engines
wilber1 wrote:No, they can't change the characteristics of the engine, but they can ensure the engine speed is kept near its peak power output as the road speed varies underneath it.they can only adapt the engines power band to the conditions, they can't change the engine speed at which the engine produces its power.
wilber1 wrote:Right. The closer the gears are spaced, the less noticeable the shift will be. With my 5-speed Hemi, dropping from 3rd (1.00:1) to second (1.50:1) resulted in a 50% increase in RPM, which is very noticeable. But a multi-speed transmission might result in only a 20% change. So from 1600 RPM, the next gear down would be around 1900 RPM. Lock that in place, take the 20% increase in power, and go.Although, I must say you barely notice it when the 8 speed ZF in my Audi kicks down a cog at highway speeds, but it is a car and isn't towing anything.
wilber1 wrote:Ah, but the article does when it says the 430 lb-ft EcoDiesel gets more work done than the 410 lb-ft Hemi.I've never said that 240 HP can do more than 400 HP
Nov-03-2013 08:45 AM
I'll agree the EcoDiesel may be able to cruise down the road at a slightly lower RPM with the same weight, but when it's time to dig deep, the Hemi will eat the EcoDiesel's lunch, and it won't even be close. And what leads people to believe otherwise is all this misinformation about peak engine torque
Nov-03-2013 08:01 AM
bimbert84 wrote:
Yes, the EcoDiesel will be able to pull more weight at lower RPMs, and I've conceded this many times. I'm not sure why you feel the need to keep restating it.
And I'm still not sure why you think that's such a big deal. The Hemi will do at 2000 RPM what the EcoDiesel will do at 1600 RPM. With all those gears, it makes it much more likely that you can select a gear that will put it at 2000 RPM to get that power, when and only when you need it.
The EcoDiesel has the same tow rating because they need to sell them. The average person doesn't understand the concepts being discussed in this thread -- all they see are tow ratings and peak numbers.
Nov-03-2013 07:58 AM
Nov-03-2013 01:24 AM
quicksilverado wrote:No argument here. But economy and power are different topics. I never said anything about which would be cheaper to operate. I only disputed the claim that peak engine torque is what gets the work done.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.
Nov-03-2013 01:22 AM
4x4ord wrote:Again, those are peak numbers. Notice how you dropped the RPM figures that go along with them? That's what most everyone does. You also left out gearing information, and most everyone does that, too. Unfortunately, those things are crucial to explaining how well a vehicle performs.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.
Nov-03-2013 01:14 AM
wilber1 wrote:Yes, the EcoDiesel will be able to pull more weight at lower RPMs, and I've conceded this many times. I'm not sure why you feel the need to keep restating it.the diesel will be more able to stay in its OD ratios pulling more weight than the hemi.
wilber1 wrote:That's just revophobia, which is the 1st cousin of downshiftophobia. And besides, you'll only "rev the snot out of it" if and when you want to get the load moving quickly! If you're content with a slower pace, you don't need all that power, so you don't need to rev. I'm not sure why this latter point seems so difficult to grasp.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.
wilber1 wrote:Thank you! And the reason for this is that the EcoDiesel has less power despite having more peak torque. This is exactly what I've been saying since I got involved in this thread. Go back and re-read my original statement: the article claimed peak engine torque is what gets the work done, and I disagreed. Now you've just reiterated my own arguments back at me, which means we're in agreement, and hopefully we're done with this circle.It just won't get up the hill as fast as the Hemi.
wilber1 wrote:The EcoDiesel has the same tow rating because they need to sell them. The average person doesn't understand the concepts being discussed in this thread -- all they see are tow ratings and peak numbers.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.
Nov-02-2013 02:10 PM
bimbert84 wrote:wilber1 wrote: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.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.
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
Nov-02-2013 09:44 AM
Nov-02-2013 09:33 AM
Nov-02-2013 02:47 AM
wilber1 wrote: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.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.