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Diesel engines, which is better: Ford, Dodge, Chevy



  • Are you sure it was a 2000 with the 6.5 in it? When we ordered our 2000 we were unable to get the diesel; we were told they didn't make them in 2000.

    As for the old C/K trucks, the older the better, our '92 K1500 is still going strong (knock on wood), even after my hubby's beating. My '84 K25 is my favorite - we're sticking a 400+ sb into that as a "toy". After the bad luck with our 2000 cc, I was about ready to get the '84 back out - but Chevy's doing a buy back on that one & we're ending up with a '02 cc diesel/allison combo...hope it runs! (To each his own, but I still like the C/Ks better.)

    Can anyone tell me what type of mileage I can expect? The dealer said everyone he's spoken with is getting around 20. We were getting about 15 with the 454 in our 2000. THANKS.
  • v12powerv12power Posts: 174
    Good luck actually getting 20 mpg in a big truck like that. If you run all highway at 55-60 mph you can do it. I can get 17-18 with a D/A chevy empty. With an empty 8k lb trailer I get 12-13. With a load on 10-12. If the load gets up around 15k and the truck pulls in fourth I got 5mpg. In my old 3/4 ton 4x4 suburban with the 454 I got 10-12 empty, 6-8 pulling.

    I had a salesman tell me he had a customer getting 20pulling 20k lbs. Take it with a giant grain of salt.

    They actually do downgrade the power output to save on the auto transmissions. They do measure at the flywheel with all accessories installed per SAE standards.
  • modvptnlmodvptnl Posts: 1,352
    You beat me to it!!! I know dodge started this trend by de-tuning for auto trucks.

    Ford really didn't de-tune as much as they didn't "increase" the latest autos to manual specs.
  • modvptnlmodvptnl Posts: 1,352
    This isn't the same "mother of all trucks" you were bragging about a short while ago, is it???

    I hate to say it but..........I TOLD YOU SO. LOL!!
  • Dodge/Cummins does de-tune the motor depending on tranny choice. (check out for the facts)I don't know about Fords. They may do things a little differently.

    The reason you can't order a Cummins HO with an auto is because Dodge doesn't make one strong enough to handle the extra power. That will all change with the new heavy duty coming next fall.

    I'm impressed with the tranny in the Ford lasting that long. Even being worked hard. I guess I misunderstood your previous post.
    As for your Duramax, I hope that Allison gets everything straightened out for you. I'm not a Chevy fan at all. I hear some really nasty horror stories about them not standing behind a product. But I hope you can get somewhere with it all.

    On a side note, does/has anybody here driven a D-max with a manual. Do they even make a manual for it? How does it compare to Ford and Dodge?
    Just curious.
  • cpo3cpo3 Posts: 6
    Can any of you Ford owners that drive the F-250 4x4 Supercab with the (6 3/4 bed)and PSD, answer a ? for me and that is how do these short bed trucks ride, do they beat the piss out of you or do they give you a decent ride when empty.
  • v12powerv12power Posts: 174
    They do make a manual for the Chev. I could be wrong but I think all three use the same manual 6-speed now.

    I have a reg cab long box F350,same wheelbase as an ext cab shortbox. Its not like the old days, these things all ride pretty good empty.
  • The Ford and GM share nearly identical (slightly different) versions of the ZF S-650 6-spd manual. The Dodge I know doesn't use the ZF, but what it does use, I forget exactly...maybe the NV gearbox?
  • jcave1jcave1 Posts: 137
    Yes indeed. Mine is now 16 months old. While it does ride a bit rougher than GM or Dodge, the ride isn't harsh at all. The 7,000 lbs seems to settle it down. Shorter turning radius is also very nice. Ya don't need 40 acres to turn the sucker around. Even the wife likes it.
  • Yes GM makes these, I have one. Quadrunner500 is right, the GM and Ford use ZF S6-650 while Dodge uses the NV 5600. I don't know how to answer the question about how do they compare to Dodges. In what way? Power? There was post a while back about enough power to drag 15,000 uphill at 85mph, I don't think I have that much power, but I can accelerate from 65 to 75 on a 7% upgrade at 11,000 feet, towing 7500lbs. 75 puts it at governed RPM in 5th. My crew cab is a much more comfortable way for a family of 4 to travel than any Diesel Dodge yet. I expected a lot from the Duramax, and it has exceeded my expectations so far. It will be awhile before I know if it meets one last expectation... Will it go 400,000 miles? I think it will.
  • saddaddysaddaddy Posts: 566
    Is that just b/c of the altitude and grade and stuff. I knew of a guys old dodge that was that way, but 75 would be too slow for passing on some roads I would think. What am I missing?
  • kg11kg11 Posts: 530
    there are 6 gears.
  • v12powerv12power Posts: 174
    400,ooo miles??? How many times do you intend to replace the truck surrounding the engine to get that far? Pray for half that and if you get lucky it will make it.
  • That's is what I am hoping for. Being able to keep the truck together for 300k miles.
  • saddaddysaddaddy Posts: 566
    I told ya I was missing something. Haha, that was it. L8r
  • mesazonemesazone Posts: 51
    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.
  • richcolorichcolo Posts: 81
    I don't intend to have to "replace the truck surrounding the engine". I currently have 175,000 on a 1991 GMC 1500 V-6, and nobody believes me when I say this, but it has the original clutch and brakes, the paint was stripped and reshot because of flaking back in 1994, and it still shines, and has not flaked...lousy primer originally, GM paid, I didn't. Now that I have the new 2500HD I do notice a few squeaks and rattles in the '91, but it drives nicer than many sedans with 50,000 miles. My wife drives a '99 Honda Odyssey which at 50,000 miles does not have any of it's original brakes, its sliding doors creak, and its seats look more worn than the '91.

    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....
  • mesazonemesazone Posts: 51
    Here is something that I've thought about for a while.

    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?
  • quadrunner500quadrunner500 Posts: 2,728
    Horsepower is the product of torque times rpm. Diesels have lots of torque but operate best at low rpm, thus lower hp than you expect.

    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.
  • mullins87mullins87 Posts: 959
    It all boils down to the bore vs. stroke relationship. Well, not entirely, fuel is a part of the equation. But in the interest of simplicity I'll leave that one out.

    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.
  • mullins87mullins87 Posts: 959
    looks like we covered both sides at once.
  • jcave1jcave1 Posts: 137
    And good job too. From both y'all.
  • plutoniousplutonious Posts: 799
    Diesel engines have a compression ratio of about 22:1, while gasoline engines have a ratio of about 10:1. As you can imagine, a longer stroke is required in the diesel to acheive the higher compression ratio and as others have already explained, a longer stroke equates to more torque. A longer stroke has a larger "leveraging" effect on the crankshaft but it will not spin as fast. And as quadrunner500 pointed out, horsepower is a product of torque and RPM. The diesel's lower RPMs (due to its long stroke) is what makes the diesel have lower horsepower figures.

    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.
  • mesazonemesazone Posts: 51
    Thanks everyone. I took small engine repair in middle school and had to actually tear down a small engine and rebuild it but that was 19 years or so ago, so I know most of how an engine works. I just wasn't sure why diesel got more torque and less HP. Now I understand.

    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.
  • quadrunner500quadrunner500 Posts: 2,728
    Having serviced Hartridge fuel injection test stands for a Caterpillar dealer, I can tell you that lots of noise comes from the injectors and pump. On these test stands, a variable speed dc electric motor drives a pump. They open up the injectors and pump an inert fluid into beakers as a test to see if they flow at the same rate. You'd be surprised how much that test stand sounds like a full fledged diesel engine.

    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.
  • mesazonemesazone Posts: 51
    Well, I can say I learned a lot of new things today. Thanks for all your information.
  • badrammanbadramman Posts: 61
    WOW I'm very impressed.
    I guess you learn something new every day.
  • warfishwarfish Posts: 117
    I am a 6 months per year camper, pulling a 12,000 lb fifth wheel with a 2001 Dodge Cummins with 3.5 gears and automatic. After 26,000 miles the truck is still rock solid. The only modification I made was to install EGT, boost and transmission temp gauges, and all they do is keep me happy with what is going on up front.
    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.
  • Indian3 -

    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.
  • quadrunner500quadrunner500 Posts: 2,728
    >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.<

    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?
This discussion has been closed.