Diesel vs gas......................

[blt2ski]

OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diesel, pro and con, I will either leave your thread, or copy and paste pertinant info to the 4 posts of pro and con of diesel or gas. This can include the GM 8.1 vs Dmax or Ford V-8/10 vs PSD etc too.

Be real and honest in you answers, not hear say, flaming etc PLEASE!

If posts are good ones, I will leave, if inflamatory or trolling in nature, they will be deleted! I will get this stick'd to the top for future parusing for those that need this type of info.

Added 6-23-04

We are getting closer to answers I am looking for etc.

Stuff like Ken's - T-Bone posts are good. There are a few others of you that have not posted, some with a 9 point question and answer type to figure out how you went with one or the other. If you are one of those, PLEASE repost in this thread. I may have to look up whom has done this and PM you, but if you think this is you, you now know what to do.

Also, for those of you with $ per gallon for either fuel right now, I would prefer to see a post with ...."in my area, diesel is typically .10 less than unleaded" then explain your numbers. As currently in the Seattle area, diesel and unleaded are any where from 2.05 -2.30 per gallon, with mid test .10 more and premium about .20 more, with equal high low splits. Two weeks ago those prices were upwards of .30 -.40 per gallon more. people were posting $ per gallon that were for me. "I wish" If someone is reading your post a year from now, they may want to know where your paying 1.65, when the price of fuel is over $3 per gallon. Let's keep prices out of it if possible.

Bert and tin tipi, got into a good discusion on the pros and cons of RPM's, drive train etc. I would prefer to NOT see the quote of the other in responding threads, maybe just write a quick wording of re tranny gearing, instead of the whole 40 words or so in that paragragh, so the repsonse is shorter if possible quicker and easier to read etc.

I have deleted some 15+/- posts, that were off topic etc. Please note, I am trying to keep this at the top, as the ONLY gas/diesel thread in this area. So if one is trying to decide, we do not have to go thru this BS any more. As such, I will be deleting ANY future posts close to resembling this type of topic. I may have to change "this" title to a better one, if one has a better sounding title, to be more positive, better claification, let me know here, or in a PM/e-mail, what ever you feel most comfortible with.

Again thank you for all of you that are keeping responses positive, etc.

Also we could use a few more positive reasons to go gas, as many can see I have both gas and diesel, both have a place! Both have positive reasons to buy that fuel, lets keep the threads etc to that purpose only!

Marty

[mgratner]

BertP,

What you said was silly. In 4+ years of fulltiming I have never been passed by a tank. This thread has gotten so far afield it should be closed.

Cigar Mike

[BertP]

Did I say something wrong? If so, please tell me what it was. You guys are trying to say that torque is a huge factor in engine performance but I have shown time and again that it isn't. In the tank example, you can have two tanks identical in every respect except for engine - one has a high torque (4000 lb-ft) 1500 HP diesel and the other has a low torque (350 lb-ft) 1500 HP turbine. Except for fuel mileage, they will have exactly the same perfomance numbers. How does torque figure into that???????

Bert

[Madhatter1]

I give up on Bert.

[BertP]

When it comes to trying to figure out the capabilities of an engine, torque never matters. Only HP can tell you what an engine is capable of - just like the AGT1500 mentioned earlier that is in the Abrams tank. It develops very little torque but lots of HP. That's why it can propell a 70 ton behemouth at 50+ mph. And it will do it in exactly the same manner as a high torque 1500 HP diesel.

Bert

[Madhatter1]

The diesels make a lot more HP down low in the RPM range. Many are just comparing max HP and torque numbers and making a conclusion. Whether its a CTD, Dmax, or PSD they all have more power down low that gas engines. The 3 have optimun torque in different RPM ranges but all are low range. BertP is asking if a Diesel can make its HP at a lower RPM than a gasser. The answar is yes as stated in my above post. Torque by itself does tell you nothing but knowing how much and at what RPMs tell the whole story about the engine. Contrary to what others are saying it is the max HP that means the least for TOWING engines. Please don't bring up a special application uncommon engine to show a gasses can produce big low RPM torque numbers. I know it can be done but not in a pickup you can buy.

[dubdub07]

BertP wrote:
Madhatter1 is correct: You need power (HP) to get moving. If you have it, you're gone. If you don't, you're parked. The more you have, the quicker you will disappear over the horizon. The problem comes when we start using words like "easier". What does that mean? Does it mean that a diesel can generate its HP at lower rpm than a gasser? If yes, then a diesl can pull a load "easier" than a gasser. If it means that an engine is useing less of its installed power then the gasser has an easier job of pulling the load (assuming that the gasser has more installed HP than the diesel and that the power losses across the drive train are equal).

No, HP is not the be all and end all. But, torque by itself tells you nothing. If it did, why do you find the power ratings for all of the big engines (ships, trains, etc) give you their HP rating and not their torque rating? Yes, you can find out what the torque rating is, but they are sold by HP because that is what indicates how much work can be done by the engine.

Bert

I think the reason they don't give the T rating is due to the HUGE amount of HP. And not to say you are right, or anything, when you have a TON of HP, T doesn't matter.

[BertP]

Madhatter1 is correct: You need power (HP) to get moving. If you have it, you're gone. If you don't, you're parked. The more you have, the quicker you will disappear over the horizon. The problem comes when we start using words like "easier". What does that mean? Does it mean that a diesel can generate its HP at lower rpm than a gasser? If yes, then a diesl can pull a load "easier" than a gasser. If it means that an engine is useing less of its installed power then the gasser has an easier job of pulling the load (assuming that the gasser has more installed HP than the diesel and that the power losses across the drive train are equal).

No, HP is not the be all and end all. But, torque by itself tells you nothing. If it did, why do you find the power ratings for all of the big engines (ships, trains, etc) give you their HP rating and not their torque rating? Yes, you can find out what the torque rating is, but they are sold by HP because that is what indicates how much work can be done by the engine.

Bert

[dubdub07]

Madhatter1 wrote:
Maybe this will simplify things. My CTD makes a lot more HP at low RPMs than a gas engine does. Lots of HP right off idle. Lots of HP that signs off at 3200? RPMs. Gas engines are just starting to come alive above 2000 RPMs. That is how it pulls my trailer easier. I can get moving quite well at less than 1/2 throttle. It is because the HP is at low RPMs that all the torque is made. You know, the torque that the gas guys for some reason want to say does not matter and that they "make up" for with gearing. Stick the weed wacker engine on there with the right gearing. This thread has turned from a sensible discussion into a "my way is the only way" arguement. Everyone seems to be making up their own facts. I choose Diesel all the way but I have no disrepect if someone pulls up with a bigger trailer than mine towing with gas. I have no idea how often, how far, or where he tows. I also have no idea what he needed to spend or what great deal he may have gotten. He has his own reasons and is capable of pulling the load, just differently than my truck.

Well put, and you are right, 3200 and she's done, but boy it sure is easy to get there. I won't win any races without the trailer, but with the 5er I spend a lot more time than you would think passing in the fast lane. I was on a pretty decent hill last week stopped at a light with the 5er in tow....sure was nice to have the low end to start up the hill.......and keep going and going.....

[Madhatter1]

Maybe this will simplify things. My CTD makes a lot more HP at low RPMs than a gas engine does. Lots of HP right off idle. Lots of HP that signs off at 3200? RPMs. Gas engines are just starting to come alive above 2000 RPMs. That is how it pulls my trailer easier. I can get moving quite well at less than 1/2 throttle. It is because the HP is at low RPMs that all the torque is made. You know, the torque that the gas guys for some reason want to say does not matter and that they "make up" for with gearing. Stick the weed wacker engine on there with the right gearing. This thread has turned from a sensible discussion into a "my way is the only way" arguement. Everyone seems to be making up their own facts. I choose Diesel all the way but I have no disrepect if someone pulls up with a bigger trailer than mine towing with gas. I have no idea how often, how far, or where he tows. I also have no idea what he needed to spend or what great deal he may have gotten. He has his own reasons and is capable of pulling the load, just differently than my truck.

[dubdub07]

You know what, I see what you are saying Bert.......an epiphany, if you will! If what you are saying is what I think you are, we are saying the same thing! It all starts with HP! You can't even MEASURE torque without HP. HP is the first, foremost and most important part of the equation.......torque is a non-player without HP......I get that and thought it was just understood, but you are right about HP. You can't sell torque without HP; got it.

[dubdub07]

deleted by me.

[BertP]

GACamper wrote:
It's no secret that most large commercial trucks and some heavy-duty trucks have diesel engines. Why? Diesel engines generate more torque.

Close: Diesels are used because they are more cost effective per mile than a similarly powered gas engine.

GACamper wrote:
Since a diesel engine doesn't have spark plugs and uses compressed air to ignite fuel, the piston has to travel a longer distance to compress enough air for ignition. This cylinder travel distance is called stroke, and more stroke means more torque.

How do you explain opposed piston diesels, then? Since there is no head (the pistonstravel towards one another in pairs) the stroke is very short. Much shorter than a gasser's.

GACamper wrote:
Look at the differences between two truck engines. A Dodge Ram truck with a 6.7-liter Cummins Turbo Diesel engine has 350 horsepower and 650 pounds-feet of torque. The same truck with a 5.7-liter Hemi gasoline V8 engine, on the other hand, has 383 horsepower and 400 pounds-feet of torque. While the gasoline engine has a little more power, the diesel's torque completely blows it away.

Blows it away in what respect? A while ago (last year?) there was a head to head comparison done of the big 3's offerings. Both their diesels and gassers were involved. The GM and Ford gassers came out only slightly behind their diesel counterparts because they had decent gearing in their trannies. The Hemi, though, faired much worse. Not because it is a worse engine but because it was hamstrung by the gearing in its tranny.

GACamper wrote:
While the two trucks have very similar towing capacities --15,650 pounds for the gasoline engine and 16,350 pounds for the diesel all that low-end power means the diesel engine will have an easier time towing things.

Please define "easier".

GACamper wrote:
Keep in mind that the Cummins Diesel engine gets that much torque at only 1,500 rpm, which is just above idle. With a diesel engine, you won't have to rev the more up to start towing because the power already exists.

OK, but what does that mean to a person taking his/her family on a camping trip?

GACamper wrote:
Because you're using more energy-laden diesel fuel, diesel engines get better mileage than gasoline ones, so you'll also be able to tow heavier loads easier and longer without stopping.

As mentioned at the top, diesels do have an economic advantage over gassers.

GACamper wrote:
At the same time, a truck with a gasoline engine is going to have a cheaper base price. Diesel engines almost always cost more than gas ones because they are built to withstand greater forces from a more potent fuel.

It isn't the fuel that makes the difference. There are plenty of gassers that make just as much, if not more, torque than a diesels (check out aviation engines).

GACamper wrote:
Typically, the bigger the towing job, the larger displacement engine you will need. Towing puts a lot of stress on the engine, so more torque will reduce wear and tear on the vehicle.

Lower rpm reduces the wear and tear on an engine, not torque.

GACamper wrote:
All of the evidence points to torque as being more important than horsepower when it comes to towing. Why? The power at low-end rpm provided by high levels of torque lets you move huge loads without much effort.

Please define "effort". It takes a certain amount of power to accelerate a load. Whether that power is generated at 100 rpm or 100,000 rpm is irrelevant.

GACamper wrote:
As stated before, some diesel trucks produce twice as much torque as they do horsepower at near-idle RPM levels -- meaning that they can start pulling something like a Camper, Rv or a boat with ease.

They need the HP to tow. High rpm or low rpm, they need the HP.

GACamper wrote:
Horsepower is important because it allows a car to move faster on the highway and at high rpm. However, if you can't get that RV off the line, all the horsepower in the world won't help you.

All the torque in the world won't get anything moving if there is no HP. If you have HP, things will happen.

Bert

[dubdub07]

Hannibal wrote:

dubdub07 wrote:

Hannibal wrote:
Torque, in our application, is measured on an engine dyno and multiplied by rpm, then devided by the constant 5252. On a chassis dyno, you measure horsepower. There's no way to "measure" flywheel torque on a chassis dyno. To many multiplications in the way. Horsepower is linear, torque is not. Acceleration of the drum against it's electrical resistance is measured and "if" you connect the necessary means of interring engine rpm into the dyno's computer, you'll only get a horsepower at road speed readout, not torque. Torque is the calculated number then using hp/rpm X 5252. It's horsepower. The little pickup truck diesels make it at 30% lower rpm.
The Hemi Screaming? 2000rpm with the diesels is 33revs per second. Hardly loafing along. A Formula One race car turning 19,000 rpm is what I call screaming. My 2500rpm towing cruise is a lot closer to the diesels rpm in comparison. Once again, perception trumps reality to most drivers. My Hemi powered duplicate of my '03 SO Cummins Ram easily out tows the 250hp/460ftlbs Cummins with 100more hp and 100ft/lbs less torque.
Torque is a twisting force, not a leverage force. Two different animals. The axle is an idler on a steam locomotive. The axle does not twist the wheel. The arm pushes the wheel. That's not torque.

You are trying to justify why you tow with a hemi, and of course, you are wrong. I have never owned a motor that "twists", they rotate around and axis, like the arm attached to a piston, whether it gas or diesel or steam.

Justify it? I don't think so. I used "my" money to buy it. The only person I need to make happy with it is "me". And happy I am! So, sorry, you're wrong.
Also, my engine twists it's crankshaft and through the transmission twists the drive shaft and after a 90* ring and pinion turn, twists the axle shaft. The connecting rods in our engines are connected to a shaft which "twists" the output power. The connecting rods of a steam engine connect to the wheels to push the wheels around. There is no twisting force. Torque IS twisting force. To say otherwise is an admission that one doesn't know what torque is.

You are so right, and the HEMI is awesome, love V-8's, dual exhaust, Dodge trucks, that is not an issue and I am NOT slamming your truck at ALL!

I do, however, bow to your extreme knowledge and you are right. Next time down the road I will look at my TPM gauge and see how many "twists per minute" my motor is doing. Are you going to write the car companies and have all the gauges fixed?

We are so far off the original discussion it will take a space shuttle flight to return to earth and talk about what is real again. Space engines, tank engines, now steam engines.......torque is just leverage generated from a turning, "twisting" or rotating force. Diesel motors have more of it that is why they tow better. Your tranny and rear gears only transfer that leverage and HP to the wheels. If you use a prybar to create leverage and lift a motor of its mount, did the prybar create the power to lift the motor? No, I did. All the prybar did is create more leverage so my weak old body could lift it. All the HP came from ME. Same as a tranny and rear end. The engine has it's own HP AANNNNDDDD torque.
I learned all this years ago.........and I have never ridden in a tank or a spaceship.....sheesh. I admit I don't know what torque is......happy. (but i do.)

[Hannibal]

dubdub07 wrote:

Hannibal wrote:
Torque, in our application, is measured on an engine dyno and multiplied by rpm, then devided by the constant 5252. On a chassis dyno, you measure horsepower. There's no way to "measure" flywheel torque on a chassis dyno. To many multiplications in the way. Horsepower is linear, torque is not. Acceleration of the drum against it's electrical resistance is measured and "if" you connect the necessary means of interring engine rpm into the dyno's computer, you'll only get a horsepower at road speed readout, not torque. Torque is the calculated number then using hp/rpm X 5252. It's horsepower. The little pickup truck diesels make it at 30% lower rpm.
The Hemi Screaming? 2000rpm with the diesels is 33revs per second. Hardly loafing along. A Formula One race car turning 19,000 rpm is what I call screaming. My 2500rpm towing cruise is a lot closer to the diesels rpm in comparison. Once again, perception trumps reality to most drivers. My Hemi powered duplicate of my '03 SO Cummins Ram easily out tows the 250hp/460ftlbs Cummins with 100more hp and 100ft/lbs less torque.
Torque is a twisting force, not a leverage force. Two different animals. The axle is an idler on a steam locomotive. The axle does not twist the wheel. The arm pushes the wheel. That's not torque.

You are trying to justify why you tow with a hemi, and of course, you are wrong. I have never owned a motor that "twists", they rotate around and axis, like the arm attached to a piston, whether it gas or diesel or steam.

Justify it? I don't think so. I used "my" money to buy it. The only person I need to make happy with it is "me". And happy I am! So, sorry, you're wrong.
Also, my engine twists it's crankshaft and through the transmission twists the drive shaft and after a 90* ring and pinion turn, twists the axle shaft. The connecting rods in our engines are connected to a shaft which "twists" the output power. The connecting rods of a steam engine connect to the wheels to push the wheels around. There is no twisting force. Torque IS twisting force. To say otherwise is an admission that one doesn't know what torque is.

[dubdub07]

robna wrote:
Ive driven both the old 5.9 ctd and the new 6.7 and have to say I still prefer my hemi I do agree towing with a diesel is better. The diesels are great tow rigs but my hemi does both fine and enjoy leaving you diesels behind me at a light no trailer of course and yes I have beaten the new 6.7 beat him by 4 truck lengths. Happy trails to all!!!

All though the 6.7 isn't a dog, it will not beat a 380hp HEMI, 4 truck lengths is a lot.........must have been quite a distance. Mine does well 0-60, but after that there is no real acceleration. I love the HEMI, owned a couple, good motor. I towed a TT with my HEMI, had a 20KT headwind and it took me 24 gallons to drive 96 miles and the darn thing must have shifted 1000 times. 6000 rpm, 3000 rpm......over and over........

CTD is designed to tow and last a zillion miles under heavy load; a feat that it excels at. Hopefully the Dodge wrapper will last half that! (I am using someone else's term "Dodge wrapper", I thought it was cool so I am stealing it) It isn't exciting but ample and tows the******out of my 5er. Another plus is it is not air asperated, so I get the same performance from her at any altitude.

Stay HEMI, avoid Toyota! Be proud to be American!!!