Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!
Diesel engines, which is better: Ford, Dodge, Chevy
This discussion has been closed.
Popular New Cars
Popular Used Sedans
Popular Used SUVs
Popular Used Pickup Trucks
Popular Used Hatchbacks
Popular Used Minivans
Popular Used Coupes
Popular Used Wagons
Comments
kip
I've got the pickup you are questioning. It will throw you around if the roads you drive on are rough. Just driving down the street/highway, it is just fine. There is a dirt area on the way home from town my boys (3 and 5) like me to drive over. It bounces pretty good which is what they like. My tires are at 52PSI.
Paul
When I was looking at the new trucks more than one dealer bragged that the new brakes on the 2500HD were designed to be 3x more durable than on the older trucks...I guess I'll still have the originals at 400,000 (I don't believe that claim myself). I expect that I'll ahve to do some interior work, but I expect the body and suspension will be in good shape until I turn it over to my soon to be 4 year old son, in 12 years. After that....
Why is it that a diesel engine can have more torque and less HP then a gas engine of the same size? Why is the gap between HP and torque larger for diesel then gas? Is it all in the fuel? Do the removal of the spark plugs have anything to do with it?
It really comes down to the fuel. Diesel fuel has more BTUs per pound than gasoline, but gasoline is more refined, and gives a controlled burn over time. Because of this, by adjusting the timing of the ignition spark, i.e. advancing it as rpm increases, a gas engine can operate over a wider range of rpms. There's not much control to the diesel burn rate. So unlike a gas engine, where a mixture of fuel and air is compressed, in the case of diesel only air is compressed. This makes the air HOT (1st law of thermodynamics). At the precise optimum time, raw diesel fuel is injected into the compressed mass of hot air causing immediate ignition. You get more violent ignition, and more power per stroke, due to the higher BTU content, but because the rate of burn is limited, so is the range of rpms over which you can achieve this.
High performance engines, i.e. race engines, have a short stroke in relation to the width of the bore. A short stroke engine turns higher rpms, therefore creating more horsepower, but not as much torque.
Tractor engines have a long stroke in relation to the width of their bore. This long stroke is not very conducive to high rpms, but will produce a lot of torque.
Torque is what actually gets the work done. That is why us truck guys talk about torque, but rarely about horsepower. A racer friend of mine described it to me this way; "Torque is what gets you there, horsepower is what keeps you there." I guess what he means is the torque is what allows you to accelerate from idle, where very little horsepower is being made, but torque is. Once you get up to speed, the engine is making enough horsepower to keep you at speed.
The spark plugs have nothing to do with it. They are simply the way gasoline is ignited, and they are not needed in a diesel engine.
I hope I have not confused you further. I'm not an expert by any means, just a shade tree mechanic who has learned out of neccessity.
But that's not the only factor that influences the diesel's lower horsepower figures. The inherent high pressure in diesels require heavy pistons and connecting rods. This combination of high compression and heavy pistons and rods also prevent the engine from revving fast, resulting in a loss of horsepower.
Also, diesel fuel is able to combust with a very lean mixture, as opposed to gasoline which requires a much richer mixture. Of course, the diesel's leaner mixture is what enables it to get relatively good gas mileage but at the expense of less horsepower.
Also made for a great conversation piece to keep this group alive.
I guess that with the "violent" explosion in the cylinder is what causes all the noise. How is it then that the Duramax is so quiet and my Power Stroke is so loud? (Why am I asking these questions AFTER buying it?) Could it be a thicker block for the Duramax?
mullins87, I've heard that quote about HP and torque. That's how I keep them separated and understandable and why torque is needed for heavier loads.
Having said that, the Duramax (like mine) isn't always so much quieter, only when the pilot injection circuit is enabled by the computer. Pilot injection (Bosch) works by squirting a pre-charge of fuel to start the combustion process sooner, before the full charge is sprayed-in later. It helps make things quite, but doesn't operate under all conditions.
I guess you learn something new every day.
As anyone who pulls a camper knows, campers talk to each other very freely about their rigs. I've met many couples who tow much larger rigs than mine with Dodge Cummins automatics and I have yet to meet the guy who says his transmission is junk. Some of these guys have 150 and 200k on their trucks and still no problems.
As far as the GM duramax/Allison rigs go, it's still early to tell, but I think most of the problems we read about are urban legends, or maybe a few stories that have been repeated so many times it sounds like a great deal more than actually have happened. I've talked to a lot of owners in the campgrounds and have not found one who is not very happy with his rig.
The Fords are OK too. With a little tweaking they are very good. But for comfort, long term reliability and the ease of access to the engine, I'll take my Dodge Cummins over the rest.
Your original question was which diesel engine is the best. Between having driven all three current offerings and older GM diesels along with public available information I would have to say the the Cummins dodge uses is the best engine. I currently have a GM diesel.
This will be even more the case with the new Cummins engine in the upcoming Dodge 2003 HDs. The will have the common rail injection system like the GM offering to improve severe cold starting and emissions and offer 305 hp and 555 ft of torque ratter at 23K pounds of towing.
It is the only one of the three engines that is rated as a true medinum duty truck engine. It seven main bearings for six cylinders and is certified as an average of 350,000 miles between major overhauls. Also, inline sixes are a more simple stright foreward design and inline engines always will run smother.
Dodge has not had an automatic transmission that has been upto the Cummins engine. They are gonig to offer a new 5-speed automatic midway through the 2003 MY but I would go with the new 6-speed manual transmission.
I can not understand why Dodge did not get their new automatic transmissions from Allison. That automatic is great but expensive.
As for which truck that hese engines are in is the best I can not be sure, but the best engine is Cummins. By the way, Ford is going to be droping the International unit in their 2004 trucks because of issues they are having with the engine.
If the noisy Cummins is already better than the Duramax diesel, why do they need to copy it?
>I can not understand why Dodge did not get their new automatic transmissions from Allison. That automatic is great but expensive.<
Is it because G.M. purchased, and now owns Allison, 100% lock, stock and barrel?
Jamesfletcher2: Is this what you mean when you say "Ford is dropping the International in 2004"
Also a comment on Horsepower and Torque. It is Horsepower that is the measure for the ability to do work. Torque is a component of an engines ability to provide that horsepower. The other component is speed. So if you want to carry a load up a hill at a given MPH, this will require a fixed amount of Horsepower, not Torque.
Another way to think of it is that it is possible to produce 500 lb-ft of torque from a 5 HP Briggs and Stratton engine by gearing the output down. But installing that package in you pickup to pull your 5th wheel up the Grapevine is not going to work very well.
As this pertains to trucks and towing. Seeing that there is a lot of wind resistance with a truck and even more when towing, the truck acts like it is always trying to accelerate and that is why it is more important to have torque than HP in a truck.
There is a fixed relationship,
HP=(Torque*RPM)/5252
Horsepower will equal torque always at 5252 RPM, and above this point horsepower will always be greater than the torque.
The reason that we want as much torque as possible for a pulling truck is that the higher the torque number at pulling RPM, the more available horsepower to pull with. This is why the Duramax has more pulling power at 2000 RPMs than the 8100. This is even though the HP is 340 on the big block, and only 300 on the Duramax. THe 8100 will outpull the Duramax if both are at peak HP levels, but this depends on the gearing situation. IT IS VERY DESIRABLE TO PULL AT RPMS AROUND 1800-2000 RATHER THAN 3000-3500 FOR THE FUEL ECONOMY, NOISE, AND LONGEVITY ISSUES.
THIS IS WHY TORQUE IS IMPORTANT ON A PULLING TRUCK, BUT IS NOT KING.
ON ANOTHER NOTE, ALL OF OUR FARM TRACTORS, COMBINES, ECT ARE RATED BY HORSEPOWER AT RATED LOAD RPM, SUCH AS 235 HORSEPOWER AT 2000 RPMS, that engine has a max governed RPM of 2200 rpms, and is 95% of the time operated at full throttle, with the load pulling the RPMS down to 1900-2100 RPMs, under no load, 2200 RPMs.
Hunter
Hope you all get it now!
The base of almost all discussions goes back to the "tried and true" diesel engines. Dodge has the Cummins engine which has made a few improvements in the last few years, however the other components the engine is coupled with will not last with the engine. My friend works right next door at a Dodge dealership and has replaced many transmissions in these trucks due to not being able to keep up with the diesel. Also, this is a great engine, but why in the next year or so is DaimlerChrysler going to give a choice between Cummins and Mercedes Diesel?
Ford with it's PowerStroke is a good choice for low mileage uses. By low mileage I am insinuating 150K or less. After this threshold, the truck loses its characteristics that made it such a good truck. Diesels are supposed to be built rugged enough to last 200-even500K miles. Seen the resale value of an older model Powerstroke lately? It isn't pretty. Also, this engine brings to the table relatively close the same numbers that Chevy and Dodge offers. The problem with this is the abundance of 7.3 liters. As well as higher maintenance costs, you also have poor gas mileage to add to it.
Now to the Chevy. This Duramax is new to the Chevy, but it is built by Isuzu. If you didn't know, Isuzu has been building diesel engines longer than any other auto manufacturer. Are far as "tried and true," Chevy takes pride in the fact that they test out everything thoroughly before producing it for the public. This in turn reduces the number of problems in the long run. Am I saying that Chevy has no problems? No, but the chances of having a major problem with your new Chevy truck is very slim. How do you think Chevy can keep its slogan "Like A Rock" for as long as it has with no hassles. If you haven't driven a Chevy, just go test drive one. The ride quality in this Diesel truck will greatly impress you.
My Sierra 2500HD has it's THIRD Allison in it.
"why in the next year or sois DaimlerChrysler going to give a choice between Cummins and Mercedes Diasel?"
How about,BECAUSE THEY OWN MERCEDES?
"Chevy takes pride in the fact that they test out everything thoroughly before producing it for the public"
TWO transmissions were taken out of my ONE truck and returned to Allison "for research"because of an electronic programming problem.
AND if you want to keep selling Chevys you can't say anything about why GM is STILL producing knocking engines after THREE YEARS.
kip
Just because GM outsourced a motor and trans from reputable manufacturers (finally) doesn't prove any long term quality or re-sale issues for it's new HD. Neither this motor nor this trans are identical to anything that has been on the road for years as they were specifically made for GM.
If these trucks are so good and somebody really would like one I suggest contacting dealers in Georgia where there are huge rebates on new 2001 Duramax's that dealers still have in inventory. Good luck finding an ad for a new '01 Ford or Dodge diesel.
As far as re-sale goes my recently traded '99.5 F-250 SC SD PSD with 90K miles depreciated only $8000 from what I paid for it new on trade and that was with X-plan on the new '02 PSD CC truck so they couldn't make up for the difference on the new vehicle as its price was out of their control. What else seats six, will pull virtually anything and only depreciates roughly 8 cents per mile with very high mileage in a relatively short period of time?
I'm also curious to see what the thick head gasket between iron block and aluminum head on the Duramax is going to do around 100-125K, but only time will tell.
As a matter of fact go back to you little cubicle and post again when the 1 millionth Duramax is placed in a HD. Ford placed its 1 millionth Powerstroke in the Turtle V Expedition F-550 on August 30, 1999 and they most likely will reach the second million mark by the end of this model ('02) year.
What I really wanted to interject, was the subject of torque and horsepower. In the simplest terms, torque is work, but horsepower is the time rate of doing work.
If you followed that, torque is Force times Radius, Horsepower is Torque times Rpm.
Being on the farm and working on equipment all the time, I assume you are familiar with a torque wrench and how it works. What does a torque wrench measure? How much force (work) is being applied to the nut/bolt. A dyno, the device used to measure an engines HP, works in much the same way as a torque wrench, only it uses a viscous fluid to measure forces applied. The engine attempts to turn the shaft of the dyno while the dyno attempts to shut the engine down by not letting the shaft be turned. This is where the torque of the engine is measured. Horsepower alone could never turn that shaft. Of course, you cannot have horsepower without some torque.
Torque measures how much work can be done and horsepower measures how quickly it can be done. I apologize for ever responding to Rick, I'm afraid I may have started another discussion on a long since worn out subject.
Anyways, on the torque, horsepower debate. Our tractors have 12, 16, 18, or say 24 gears to allow us to go the proper speed in the field. One tractor for example makes 220 Horsepower at 1900 RPMs, and another tractor makes the same horsepower at 2600 RPMs. They both will pull the same load, but have different torque curves and numbers. It is the producing of a given amount of horsepower at different RPMs, and using gearing to provide equal ground speed that allows the same amount of work to be done.
Two engines of the same horsepower, one produces 600 ft lbs at 1500 RPMs, and the other produces 400 ft lbs at 1500 RPMs, the one with the 600 ft lbs, will pull 50% more than the other one at that given RPM, but both at peak HP, will pull equally.
HORSEPOWER IS MEANINGLESS UNLESS YOU KNOW THE RPM THAT IT IS PRODUCED AT AND YOU ARE AT THAT RPM (want to be at that rpm doing the work), TORQUE IS MEANINGLESS UNLESS YOU KNOW WHAT RPM IT IS PRODUCED AT, WHICH ALLOWS YOU TO CALCULATE HORSEPOWER! HORSEPOWER TAKES BOTH TORQUE AND RPM INTO CONSIDERATION TO GIVE POWER AVAILABLE FOR WORK.
Hunter
Oh, and Chrysler doesn't own Mercedes. Mercedes bailed Chrysler out when there business was down in the dumps. I worked for them when that merger took affect. I a sense, it hurt Mercedes more than it helped Chrysler because now Mercedes has to take care of all the problems.
26PSIBOOST- Good luck finding huge sales on '01 Dodge Diesels? Our Ford and Dodge dealerships have their diesels marked down to close to $21,000 just to try to get rid of them. The problem with Dodge is that the new body style is hurting the heavy duty trucks. People would rather wait another year to get a new body style than get a new '01 and have the resale value drop after they redesign them.
Your trade-in value is easy to make seem higher or lower than what it should be, even if you have a fixed price. Check out the real trade-in values through Edmund's or Kelley Blue Book. Don't be fooled by your obvious inexperience. Trust me, I was fooled once when I was younger. It won't happen again to me. But I also know the car business better now.
Torque is really not work, it is rotational force. Or to say it another way, it is force acting at a distance (radius).
Work is force acting through a distance (pushing on an object with 5 lbs. of force for a distance of 5 feet is 25 ft-lbs. of work).
And Power is the rate of doing work (pushing that same object 5 feet in 1 sec is 25 ft-lbs/sec or .04545455 horsepower).
And for those of you out there that are wondering why this is so important, it is because this does have relevance to owning and enjoying trucks. Trucks are about pulling, hauling, acceleration, torque, horsepower, work and cool stuff like that.
On the Duramax, GM grossly underestimated the demand for this marvelous engine so they are capacity limited. This is the reason for the long waits. They could have sold 50% more if they had the production capacity. You can be assured that they are addressing this as we speak.
I didn't say my truck is a P.O.S. but you must admit it wasn't ready for market when it was released 3 or 4 months late.
kip
Force equals mass times acceleration.
Work equals force times distance.
Oops! That makes you right and me wrong. Thanks for correcting!
However, if you are ruling out the Chevy, and you want a 6 speed, I would go with the Ford over the new Dodge.
This will be a new truck with many new parts. Historically this proves to provide some unreliable vehicles while the manufacturers work all the bugs out.
Personally I believe the new Cummins will be a great reliable engine, but I would be concerned about the electronics controlling it and the rest of the truck.
The PSD has proven itself, and with the manual tranny it is a great package.
I agree wholeheartedly about the problems with autos.
So far I have 106+ on mine with no problems.
The ZF is a good transmission too. My only complaint on the one in our '94 Ford F-350 Crewcab, SRW is that it just won't synchro-shift like the NV-4500. Of course the clutch is a lot lighter in the Ford so it evens out.
Texas Truck - r
I need to get a new vehicle in the next six months or so. I am considering a 3/4 ton diesel. It will only have to pull a 2-horse trailer for the next year or so (5500lbs total) 4-6 times/month between May and October on mainly short hauls of less than 60 miles. I live in Maine, so it is not totally flat. But then I might get a 4-horse and be up around 9-12K lbs depending on the configuration). What are the advantages of the diesel? Disadvantages? Does it only make sense to pay extra for the diesel if you haul all the time or plan to run the truck into the ground and keep it forever?
TIA for any and all suggestions,
Dino
The advantages of the PSD: durability, longevity. The disadvantages: the oil changes will cost you about $35 for the oil and filter, 15 quarts of oil! Plus there are other maintenance items as the fuel filter, air filter, coolant additives, I'm sure I have left something out.
Depending on fuel prices and your fuel mileage, seems the break even point on a diesel purchase is around 100k miles. Remember, that diesel option will set you back about $4,500 up front, you get that back in fuel mileage savings over the gasser. Figure around 18 mpg empty with the diesel and around 13 mpg with the V-10.
I have a '99 F-350 dually PSD. First off, I love diesels, so my decision was as much a love affair as it was what I "needed". I could have gotten by with the V-10 very easily considering what I pull. But, the deciding factor for me was the longevity issue. With the mileage I drive, my truck will have approximately 300k miles before I can get another one. I don't expect any gasser to make it that far, although it has been done. My annual fuel bill has dropped a little over $1,000 since I bought the PSD. My truck has over 100k on it so far, so I am almost to the break even point on my truck. This winter the diesel option will have paid for itself.
If you are going to put 75k miles on it, then trade it in, I'd say get the V-10. But, if you are going to put LOTS AND LOTS of miles on it, get the diesel.
I am looking to buy a used 94-98 fullsize truck,ext. cab or quad.( need room for a car seat and work stuff) I have a "99" with 115,000 miles on it. I don't do any towing. But i do need a truck that i can be comfortable in and that will last, i'm very good at maint. scheds. What would be better a gas truck or diesel? I was thinking about a 6 cylinder diesel because i don't tow , just a 165 mile r/t commute to work 6 days a week any info would be helpful
I remember seeing a "conversion" kit in the JCWhitney magazines that looked to be a spacer and bolt extensions to attach another standard rim outside the existing rim.
It may have been totally cosmetic. I don't remember if there were claims of effective load distribution across the extra tires.
There are 4x4 shops here in Northern Nevada that can set up just about anything you want. Must be some there too. Keeping the 4X4 gear ratios correct for the front to back is just part of the deal.
Cost vs safety. Blowing tires can't be very safe.
Good luck.