future diesel

Z71-cummins · July 25, 2005

So is Chevy gona go to a catipillar diesel or a john deere diesel. I knwo for a fact that if they put john deere diesels those would be so reliable i would pay extra to have one or evena catepillar diesel at that. what yall think?

willieboy · July 25, 2005

I think they will go with the Duramax diesel since they own the plant...

Scyry · July 25, 2005

GM jointly built the Duramax with Isuzu and now owns Duramax outright. So Duramax will be the engine of choice for a long time. Plus Isuzu sells more commercial, diesel trucks than any manufacture, so they brought some good experience to the table. Add in the Allison behind it and you won't find a better truck out there. Just wait until the Allisons appear in the 1/2 tons, no one will be able to touch Chevy power trains.

Jpshostr · July 29, 2005

I knwo for a fact that if they put john deere diesels those would be so reliable

You mean the same John Deere diesels that are shelling crankshafts left and right this year?

Shawn T · August 1, 2005

Why is everybody so fixated on this whole CAT rumor. They don't even build a small diesel, who is to say it would be any more reliable or powerful than the Isuzu designed Duramax. I have heard more good things about Dmax's than the other two. I also know people who have switched from either Ford or Dodge diesels to the DMax. Never the other way around. The Cummins or the Powerchoke are far from bulletproof and they are big names like CAT. I think that is alot of it too, the name. Alot of people would rather say they had a CAT or John Deere under the hood than an Isuzu.

Shaners · August 2, 2005

Look up diesel engine history and see where Isuzu falls... They have been in the game one heck of alot longer than anybody realizes!!!

I think GM did themselves a great favor when they opted to partner with Isuzu to develop the Dmax!!!

Shawn T · August 2, 2005

Look up diesel engine history and see where Isuzu falls... They have been in the game one heck of alot longer than anybody realizes!!!

I think GM did themselves a great favor when they opted to partner with Isuzu to develope the Dmax!!!

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Dito!

kc5deb · August 19, 2005

Gotta disagree a little on diesels here. I will give GM this; they finally got a diesel engine with power. They've flopped so many times before. The 5.7 conversion was a flop, the 6.2 was a gutless wonder, and the 6.5 wasn't all that grand either. The duramax finally has some "umph" behind it.

I think the big 3 diesels now are close to being neck-and-neck, but, they still have their own purposes.

Ford has shot themselves in the foot, IMO, for ditching their 7.3 powerstroke. They had good power, and after years of problems, had finally got them all worked out. Then, they went with a smaller displacement engine, and are just stuffing more air. That equates to a hell of a turbo lag. I know a ton of people who traded in their 7.3 to a new 6.0 cause of "more power", but, were very disappointed when they latched on a trailer. No power on the bottem end. It's gutless until you finally get enough air through the turbo to start making power, and a lot of Ford fans are really griping about it.

Duramax has the same problems that the powerstrokes have. No bottem end power until the turbo kicks in, and it seems to be getting worse as the engine is refined. I've talked to numerous duramax owners who have traded their older duramax for a new one, and see a significant loss of power on the bottem end, and have a hard time moving a heavy trailer until the turbo kicks in.

Dodge has the best torque curves in all the dyno charts I've seen, and from the people I've talked to who have owned powerstrokes and duramax's, they all swear by their cummins for pulling trailers. You have nearly 400 ft pounds of torque at only 1800 rpm, and that's what gets a load moving, and you keep a good nearly flat line most of the way through.

I have pulled a few trailers with diesels; mainly powerstrokes and cummins, and I gotta say, the cummins just seems to be the better engine for pulling. You just can't be the torque that inline 6's seem to crank out. As for horsepower, the powerstroke and duramax seem to be better.

I won't say that the duramax is junk, because it's not. It has a good flat torque curve, and Izuzu is a good manufacturer of diesels. I just think it needs some more years of engineering to get up to par with the cummins.

If anyone needs to develop a better diesel, I'll have to say it's Ford. They've had speculation of a 6.4 twin turbo diesel, but, that just sounds like a nightmare. I know International has been around a while, but, coming from a farming background, they've never been the "power leader". If I were Ford, I would re-engineer their 7.3 with a bigger turbo, and make it run circles around their 6.0, or, find someone like Cat to help em design an powerful and efficient smaller inline 6 diesel that can compete with cummins.

My opinion is that if you want a diesel that you can chip and run with the turbocharged rice rockets, you may be better off with the duramax or powerstroke. But, if you depend on your truck to pull a load down the road, you will probably be better off with the cummins.

But, opinions are like butts. Everyone has their own, and everyone think's everyone else's stinks.

gave20 · August 19, 2005

Looks to me the duramax makes 400lb/ft at 1200. I can't find a chart on cummins but more torque at a lower rpm means more umph.

Timberwolf · August 19, 2005

Looks to me the duramax makes 400lb/ft at 1200. I can't find a chart on cummins but more torque at a lower rpm means more umph.

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I have to agree with the above post. The LB7 Duramax developed max torque at 1800 RPM, the LLY at 1500 RPM. Seems to be getting better not worse. I'v had experience with both and the LLY has better throttle response, and in my experience, less turbo lag than the LB7. As far as Ford bringing back the 7.3, they ditched that motor to get better emissions. I wouldn't count on it ever coming back.

kc5deb · August 19, 2005

Depending on where you look depends on what results you get for dyno results, apparantly. I went googling for some dyno runs, and found 2 that I felt were un-biased; one from edge performance and one from hypertech.

The above shows 1800 rpm to be only about 300ft lbs.

BUT

shows 1800 rpm to be between 350ft lbs and just under 400ft lbs.

I would tend more to believe the hypertech dyno chart over the edge dyno chart, since after looking more into the edge's charts, they don't seem to show any difference in any of the duramax engines.

The hypertech chart for an '02 24v cummins is

Seems to be a little higher in torque than the duramax.

Again, let me state, I'm not trying to take away from what GM is finally doing by getting a good diesel engine. They seem to be really going forward and making progress, and I hope they continue to do so.

EDIT*

Just ran across hypertech's dyno chart of the '02 HO 24v cummins with the 6sp manual. Big reason why I'd never buy an auto tranny to pull anything.

I wish hypertech had posted some results from the duramax with a manual tranny; would be interested in seeing that...

Jpshostr · August 22, 2005

I'd have to agree with the above post in every area. Pretty well sums up what I've been saying on this forum for several years now, you want a go fast motor, get the V-8, if its a work motor get the I-6. Ease of getting more torque out of an inline engine is simply in its design, you can't rewrite physics as much as you would try.

With my work truck, used to be an 02 7.3L, now its an 03 6.0L Powerstrokes, I pull loaded trailers over quite a few miles, have gotten quite a bit of experience with them. There is one Chevy in our fleet which I've used once....and only once. I'll just say my Cummins will completely blow these things away in towing ability (I'll throw in empty as well). Sure, both configurations will pull the trailers at interstate speed the same way, but getting there is a whole different ballgame. Gotta have those V-8s WOUND out close to 2500-3000rpm to get the thing moving, until you have that turbo boost built up it can't get out of its own way...makes for some interesting intersection pullouts..... With the Cummins its just drive with no worries and no fear of the engine crapping out on ya.

As has been said before, for me work means everything with speed coming in on further down the list. If I wanted to go fast while hauling three gallons of milk, I'd have bought a freaking car and put a fart muffler on it.

Shawn T · August 22, 2005

I'd have to agree with the above post in every area. Pretty well sums up what I've been saying on this forum for several years now, you want a go fast motor, get the V-8, if its a work motor get the I-6. Ease of getting more torque out of an inline engine is simply in its design, you can't rewrite physics as much as you would try.

With my work truck, used to be an 02 7.3L, now its an 03 6.0L Powerstrokes, I pull loaded trailers over quite a few miles, have gotten quite a bit of experience with them. There is one Chevy in our fleet which I've used once....and only once. I'll just say my Cummins will completely blow these things away in towing ability (I'll throw in empty as well). Sure, both configurations will pull the trailers at interstate speed the same way, but getting there is a whole different ballgame. Gotta have those V-8s WOUND out close to 2500-3000rpm to get the thing moving, until you have that turbo boost built up it can't get out of its own way...makes for some interesting intersection pullouts..... With the Cummins its just drive with no worries and no fear of the engine crapping out on ya.

As has been said before, for me work means everything with speed coming in on further down the list. If I wanted to go fast while hauling three gallons of milk, I'd have bought a freaking car and put a fart muffler on it.

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I have a buddy who drives nothing but Cummins. I agree, the hole shot and pure low end torque award goes to the I-6 Cummins. My Dmax takes a few seconds to wake up when taking off with a heavy trailer (it can be scary sometimes in heavy traffic). On the other hand. We have pulled identical loads over Isenhower and Vail passes, side by side. When the grade gets really steep and you want to maintain 80 mph, the V-8 cannot be beat. When it downshifts the RPM increase actually helps and accelerates. When his Cummins is "forced" into a downshift sometimes the RPM rate takes it off of the torque curve. I admit he will get me on the slow windy stuff, but I take him on that section of I-70 everytime.

FH-Leader · February 16, 2006

Man i dont know where to start to tear into you guys. for one thing cat does make a small diesel! If you could put a allison trany behind a cummins it would haul. I hate my 4 speed auto, it sucks. you have to put a manual behing it.

Think ford owns cummins they are going to be taking them out of the dodge and be putting them in the fords rumers haves it and dodge owns detroit and mercades so dodge is pritty well off. The one question is how will chevy handel this the solution is make an aliance with cat or jhon deer. I would like to see a cat but what do i know im only a diesel tech.All you need is chevy auto put behind a cat and you will have a hauling sob.But i say again what do i know i only work on diesel engins for a living.

"I would rather be cummin then stroken"

O ya the straight 6 will beat a v-8 any day more low end torq thats how we get those 90,000 pound loads rolling.

Mark_in_Tulsa · February 16, 2006

Man i dont know where to start to tear into you guys. for one thing cat does make a small diesel! If you could put a allison trany behind a cummins it would haul. I hate my 4 speed auto, it sucks. you have to put a manual behing it.
Think ford owns cummins they are going to be taking them out of the dodge and be putting them in the fords rumers haves it and dodge owns detroit and mercades so dodge is pritty well off. The one question is how will chevy handel this the solution is make an aliance with cat or jhon deer. I would like to see a cat but what do i know im only a diesel tech.All you need is chevy auto put behind a cat and you will have a hauling sob.But i say again what do i know i only work on diesel engins for a living.

"I would rather be cummin then stroken"

O ya the straight 6 will beat a v-8 any day more low end torq thats how we get those 90,000 pound loads rolling.

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First of all Roger Penske bought Detroit Diesel from GM in 1988 . Dodge does not own it, nor has it ever. Dodge (Daimler-Chrysler) does own Freightliner, which uses DD but does not own DD.

2nd. Cummins are already in Fords. In the 450 or 550 and up.

3rd Cummins is presenting a rumored 440hp, 760lbs feet of torque in it's new 6.5L I-6 to Dodge to help reassure that they renew their contract.