bimbert84
Explorer
Joined 22 years ago
User Profile
User Widgets
All Activity
Re: Rear axle ratios and impact on towing
rexlion wrote: But won't the tranny simply choose a higher gear to offset the 10% difference in rear ratio, so that in the end the engine will run at pretty much the same RPM as otherwise? The short answer is yes. It's all about final drive ratio, which includes gearing in the transmission, rear end, and torque converter. As someone else pointed out, the main difference will be in launching from a stop: since both will be in 1st gear, the rear-end ratio makes the only difference. With an 8-speed transmission, the 3.45 will have you shifting into 2nd gear halfway across the intersection. With the 3.09, it'll be 3/4 of the way across. -- Rob402Views0likes0CommentsRe: Ram 1500 diesel review
wilber1 wrote: I would call that dumbshiftaphobia. Put it in D with the cruise on, not knowing what it is doing or why. I know full well what it's doing and why. Is it your nature to be unnecessarily rude? wilber1 wrote: Sure cruise in 7th or 6th instead of 8th with a higher noise level and fuel consumption. Only when and if I need to. wilber1 wrote: Put up with frequent shifting and the wear and tear that goes along with it just so you can get up a hill faster. 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. wilber1 wrote: 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. 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). -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
Turtle n Peeps wrote: Or to put it another way: The Ecoboost will eat the EcoDiesel's lunch, and it won't even be close. Well sure, because we're talking about 365HP vs. 240HP. But that difference won't be as dramatic for a couple reasons: The EcoBoost has less power than the Hemi; The EcoBoost is mated to a 6-speed tranny instead of an 8-speed, which means it'll spend less time in its powerband. On the other hand, the EcoBoost's power curve is more similar to the EcoDiesel's in that it peaks lower in the RPM range. So the EcoBoost is probably higher than the EcoDiesel at any vehicle speed, but not by as much as the Hemi at higher speeds. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
wilber1 wrote: 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. 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. wilber1 wrote: Just because it doesn't get up a hill fast enough to suite you doesn't mean it can't tow as much. Actually, that's exactly what it means, by definition. At whatever vehicle speed you choose, the one producing more power can pull more weight. wilber1 wrote: Yes, multi speed transmissions make a difference but they do it for all engines 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. wilber1 wrote: 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. 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. wilber1 wrote: 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. 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. wilber1 wrote: I've never said that 240 HP can do more than 400 HP Ah, but the article does when it says the 430 lb-ft EcoDiesel gets more work done than the 410 lb-ft Hemi. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
quicksilverado wrote: 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. 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. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
4x4ord wrote: 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. 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. So I'm not disputing it handled the load just fine. What I do often dispute are claims about why, and this thread is no exception. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
wilber1 wrote: the diesel will be more able to stay in its OD ratios pulling more weight than the hemi. 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. wilber1 wrote: 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. 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. wilber1 wrote: It just won't get up the hill as fast as the Hemi. 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. wilber1 wrote: 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. 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. You can tell me all day long that the EcoDiesel with 240HP can tow as much as the Hemi with 400HP, but that doesn't make it so. 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 being everything. That said, one should certainly ask if 400HP is really needed, or is 240HP enough? I would say that for anything towable by a half-ton, 240HP is enough 99% of the time. 240HP is a lot of power. Most folks think they need more because they look at their engine's peak numbers (surprise) and realize there are times when they wish they had more. What they fail to realize is that although their engine can generate 400HP, it rarely does because most of the time it isn't running in its power band. I think these new transmissions are going to change the way we think about towing. Soon people will start realizing that 240HP is enough, as long as we have a way to get it to the road when we need it. And I think the EcoDiesel will do that very well. But to claim it can do as much as a 400HP engine is just wrong. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
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. -- Rob474Views0likes0CommentsRe: Ram 1500 diesel review
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. -- Rob230Views0likes0Comments
Groups
Travel Trailer Group
Prefer to camp in a travel trailer? You're not alone.Mar 12, 202544,028 Posts
