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Initial Impressions - Cummins vs Duramax

8K views 27 replies 18 participants last post by  dieselgeek 
#1 ·
Just took delivery of the Cummins 6 speed. Many surprises.


#1... 34 gallon fuel tank on a short bed - WOW!



#2... Incredible torque. You rarely have to downshift. First manual transmission I ever drove that required so few shifts. You do not even throttle it to start out or back up.


#3... That fuel computer must be wrong. I reset it, then reset it, then reset it again. 65 to 75 mph driving showed 22mpg. The truck has just now turned 100 miles.


#4... Quiet and smooth riding at higher speeds. High off the ground to look around.


#5... Michelin tires standard.


#6... You can see the engine uncluttered with pipes and electrical connectors.


Just a start but these are major, major improvements over the Duramax.
 
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#3 ·
Sorry,,,but I can't keep quiet about this.


1st- may I offer my condolances. I'm sorry to hear about your predicament


2nd- You bought a wonderful motor, could well be the best of the three. To bad it only comes in a POS dodge truck


3rd- (Cummins vs Duramax ) ? Not sure I understand your comparison,,,only your 2nd item mentioning torque is a comparison. The rest of them has nothing to do with a DMAX. Not sure what all the MAJOR improvements over the DMAX are,,,,,,,


Don't take any offence to this. It's only my opinion, and not a direct attack on anybody.
 
#4 ·
RUBBERFISH,


Let's try again with more detail. Remember - I only have 100 miles on the Dodge and really don't know much about an implied "bad reputation" Dodge may have. New comparisons start with the *** I should have included this as I forgot many readers here are NOT familiar with the Duramax.


#1... 34 gallon fuel tank on a short bed - WOW!
*** Short box Duramax's only have 26 gallon tanks. Absolute BS for it to be that small. This is a major factor for those that tow.


#2... Incredible torque. You rarely have to downshift. First manual transmission I ever drove that required so few shifts. You do not even throttle it to start out or back up. *** My Allison would downshift to 4th at places where the Cummins just hummed along in 6th. The Allison was a busy transmission even after reprogramming. Downshifting is both a sign of lower torque and a pain in the .....


#3... That fuel computer must be wrong. I reset it, then reset it, then reset it again. 65 to 75 mph driving showed 22mpg. The truck has just now turned 100 miles. *** Most in-town Duramax driving showed me about 18 mpg. Is the Cummins better? Mileage will tell.


#4... Quiet and smooth riding at higher speeds. High off the ground to look around. *** The GMC was smooth also. I thought the Dodge was rough. I was wrong and....you can see "skirts" (dirty old man) way better from the Dodge.


#5... Michelin tires standard. ***Trash factory tires on GM trucks. Bridgestone/Firestone tiny donuts wear out fast.


#6... You can see the engine uncluttered with pipes and electrical connectors. *** Open a Duramax hood. Somewhere under all that maze of wires, piping and clutter you will find an engine. My opinion is that's a disgrace that makes service difficult AND offers more opportunities for trouble.


How'd I do?
 
#5 ·
captainmal said:
#3... That fuel computer must be wrong. I reset it, then reset it, then reset it again. 65 to 75 mph driving showed 22mpg. The truck has just now turned 100 miles. *** Most in-town Duramax driving showed me about 18 mpg. Is the Cummins better? Mileage will tell.

My neighbor bought a 3500 SRW CC with the R48e two weeks ago. His computer was telling him the same thing until he filled up the first time. He really averaged 14 mpg and was unhappy until I told him it will get better with time.


Driving CTD and DMax back to back impressions:


CTD felt faster unloaded, throttle was softer..


Allison is much smoother than R48e...


Rack and pinion steering kicks a$$...


Dodge exhaust system already rusting, demanding to be replaced..


Stock DMax w/22K miles much faster at 17k lbs than new CTD..


Enjoy your new ride, its going to be a money pit like DMax until you get it the way you want it.
 
#6 ·
Aketay,


I think you are right about the fuel issue. I now have 160 miles on the truck and it is showing just shy of 3/4 tank. Not sure what that is but I guessed around 10 or 11 gallons. Most all city, nasty driving as the new "money pit" has cost me around $1,800 today for cap, steps, filters, fuel tanks etc.


Everything needs to be ordered and/or made. I show nothing for the money.


Agree with you about the exhaust. I see rust where the hanger is welded onto the tailpipe at the rear.


Delivering a 41 ft. safety trailer to Austin, TX. Leaving Monday. Next weekend I will post impressions and details after this first tow.


Thanks for the info.Edited by: captainmal
 
#7 ·
captainmal,,thank you for not taking my opinion personaly
. Like I said, it was not meant to be a direct attack on anybody. Maybe I'm
<DIV>jealous of the fact that I can't get a Cummins in a GMC. In my opinion, that would be the ideal setup. I'm sure the fuel milage will pick up after a good break in period. Some have said this can take up to 10,000 mi. I'm glad to see you chose the hand shaker as apposed to the auto. That weeds out a ton of troubles and expense. If i'm lucky, one day they'll offer a Cummins in a GM,,,,put me down for 7 of them, a different color for each day of the week
. I better buy a lotto ticket for that as well. I hope Dodge has made some improvements for the 03 and 04 models, and I hope the truck serves you well for many years. It doesn't seem to matter what brand of truck we choose to buy, it's going to have a few troubles, kind of like our women
</DIV>
 
#8 ·
Captain Mal,

Good Luck Buddy,
Hope you have great luck with your new rig & enjoy it a-lot- sounds like you've earned a break in the action!
Maybe you'll come back on the -Next One- maybe, LLY or possibly a Diesel/electric hybrid, huhhh ??
I pray with my new DMax (build date week of Nov.24)....that I won't have any woes like you've been thru , real sorry for all the BS & all.
Again, Best of Luck & keep us posted. (I have friends w/ Dodges)..
Two Dogs, Paul
 
#9 ·
Rubber...& 2 dogs,


We really do think alike. I would just love a Cummins in the GM truck - "hand shaker" and all. The LLY motor is real interesting to me and I WOULD have bought another GMC with the LLY if that were possible.


Honestly, I'm kinda scared of this Dodge. There are only two grease points. Everything is sealed and that may mean future problems. I do see rust starting in the exhaust hanger welds. I do see cheap clamps on the heater hoses and have heard stories of lift pump and UV joint replacements. All that is minor compared to the troubles I've had.


On the other hand there sits that beautiful motor. Fuel filter so simple to change, new 15,000 mile oil change intervals, larger fuel tank, lots of inside-cab storage, 17" Michelin tires, huge springs but decent ride, and an overall 'rugged' look. And there sits that beautiful motor....sorry, I said that before.
 
#10 ·
Somebody's having fun. That inline 6 should give better fuel mileage, shouldn't it Capt.Mal? What's your towing capacity with a fifth wheel? (You pull your trailers with the rear hitch tho, don't you?)


Rubberfish- the big difference betw. the trucks and women is - we pay for the women our whole life.
Good luck Lawrence.


zip
 
#11 ·
Cap


Only big problem I have herd of is the lift pump going weak causing injector problems, most guys are installing a pressure guage in the cab and when the pump starts to loose pressure they have it changed, this way they eliminate injector problems. I am sure cummins will chime in on this before long and do something about it. Standyne makes a lift pump that the guys are using that has a 10,000 hr service. Hope it lasts that long cause this is the one I chose to use. Good luck with your new ride.


Geno
 
#12 ·
I hear the oil filter ain't so easy to change mal.

As far as Dmax clutter. I'm impressed with the DMax. I think it's well done compared to the Fords but can't compete with a little inline 6

Happy shiftingEdited by: hoot
 
#13 ·
Grease nipples


I don't know about the DMAX'S, but my 97 didn't have grease nipples on many of the front end components either. Replaced most of that at 40,000 kms, I guess 25,000 mi. Idler, pitman, lower ball joints, outer tie rods. Then a while later, both CV joint assemblies, and later still, today as a matter of fact, I did the posi carrier, holy crap, I own a POS as well
. Doesn't anybody make a reliable truck anymore?
 
#14 ·
Rubberfish- the big difference betw. the trucks and women is - we pay for the women our whole life.
Good luck Lawrence


No S***,,,, and some of us,,, me included, are dumb enough to do it twice
,,,, like the first one didn't cost me enough
.
 
#15 ·
Hoot & 'Rubber,


Max. trailer weight on the truck I have is 13,200 lbs. That varies by model but I see it goes up to 16,400 lbs. I see no destinction for 5th wheel or ball trailers but do not have a detailed towing guide. What I pull varies from 8 to 11,000 lbs. First pull for me it starts Monday - Pittsburgh area to Austin, TX. I'll report on that next weekend.


Fellow I know stopped last night. He has an '01 Cummins. At 114,000 miles his repairs have been limited to driveshaft joints under warranty. If they do it again he will get aftermarket ones with grease fittings. He also expects lift pump trouble but nothing so far.


I would be interested in some kind of pressure guage to monitor the pump. Have not heard of anyone doing it and how it's done. Must keep my ears open on that one.


Neighbor at the farm nearby has an '03 generation 3 Cummins. He's towing to Reno right now with about 65,000 + miles on it when he left. He had a '99 one before that. Never did a repair but I don't remember the mileage. No repairs or adjustments on his new one yet and the original tires look real good. I remind myself my Duramax was just heavenly for 117,000 miles. Then it went to hell and just didn't seem reasonable to fix at the end.


Unless I rebuilt the Allison and/or replaced the injector pump it would not be able to tow at all. As soon as any kind of weight was on the truck the transmission started to lock in gear, slipped and the injector pump did not keep up with the computer demands for pressure. Noone could diagnose a clear problem and that was part of the problem. The pump held 22,500psi under multiple tests. While towing only, there was a problem between it and the transmission. It became an 'unfixable' problem - I had already spent over $6,000 fixing fuel problems and more repairs could easily double that. With close to 20 recent breakdowns I had to call it off.


Notice how I put that paragraph in the middle of this where few will see it. There's lots you don't know. I am real lucky to not have been crashed and/or injured by the multiple breakdowns. It was a real version of hell to drive for the last few months.


I've watched the neighbor change his oil filter. The job looked easy. The filter is a long can, vertical position and unscrews from the bottom. Sort of a reach up with a wire bundle far below to one side but plenty of arm room as I viewed mine. 15,000 mile oil change recommendation from Cummins. That is not a misprint. 15,000.


One directive is to pre-fill the oil filter before putting the new one back on. Fuel filter is also the same pre-fill and is self priming. It's uses a 3/8 drive socket or 1 1/8 " wrench to take the screw cover off at the top. I hear, and it looks like as simple operation. Friends' '01 fuel filter sits higher than mine and looks easier to do. Done from the top he tells me it's a 5 minute, no hassle job.


I already checked to see how the water drain works on the fuel filter. Big yellow knob about as hard to turn as a sink faucet. Simple and easy.


Never have I driven a "hand shaker" that needed so few gear changes. Shocking torque unloaded and it pulls smoothly uphill in 6th gear from about 800 rpm. Again, not a misprint. I would not believe what I just said if I were you. Today I was on a rural road and forgot to downshift from 3rd while crawling along fooling with the compass. I think the engine got to about 600 rpm and just hummed up a slight hill with no throttle. It got me wondering if this engine can be stalled. I easily start out in 2nd gear with no throttle.


My wife and I have only been married 20 years. Was married to my first wife for 6 years. Still paying for those 6 years today. Hope I don't have to pay for these 20 like that.


More to come on ...."As the Stomach Turns".
 
#16 ·
a buddy of mine just traded an 01 cummins, for an 03 or 04, not sure. sweet truck very QUIET unusually quiet for a cummins


He pulls a travel trailer and says the new one is much more powerfull.


we have a freightliner rollback with over 300,000 miles on it (98 model) has the 5.9l cummins.


if your truck holds up, enjoy, because im sure the engine will
 
#17 ·
Rubberfish said:
2nd- You bought a wonderful motor, could well be the best of the three. To bad it only comes in a POS dodge truck

I dont know if I'd go that far... Tell ya the truth, I'm a die hard Chevy fan. I've owned nothing but GM products (with the exception of a few Japanese sedans and this Dodge CTD) all my life. My last truck was an '89 K2500 350/700R4, and the truck before was an '82 K5 Banks 6.2 Turbo/TH400. I've got a sticker on the side of my hunting trailer of Calvin peeing on a rams head. My father has an '03 D/A 2500HD, my little brother has a '99 F350 Super Cab 'stroke.


Having driven and ridden in all three trucks IMHO they all excel and suck at the same time. The F350 feel's rock solid, Ford did good with the new superduty. The cab is like a bank vault. Too bad the motor is a gutless pig. The '03 Chev is one of the most ugly trucks on the face of the earth. It has acceptable power and an awesome transmission, but a severe lack of ground clearance. Even though it is a 4X4, its sit's a bit low for me. The driver is insulated from the fact that he's driving a truck - and that could be good or bad depending on you point of view. Knowing past GM reliability issues, I'm sure the niceties such as the electronic transfer case, power windows, door locks, mirrors, etc, will all be cause for problems by the time the truck reaches 100K miles. Also - The IFS, while providing a very supple ride, will turn into a nightmare, as it did on my '89 as the miles roll by. My Dodge.... Hmm.. It rides like a beast (Front spring replacement didnt help), it creaks and groans a bit under power (Engine is approaching 1000 ft/lbs of torque, a tad more than the frame was designed for), you cant carry a cell phone conversation in it for long as its so loud inside. But, it 98,000 miles, its been to the shop once for a leaky yoke seal in the rear - thats it. All the electrical bits and pieces are still working in unison, there is no significant driveline lash, and it still tracks relativley straight down the road.


Dodge is a POS??? I think not... None of the big 3 makes a POS.
 
#18 ·
BIG RUSS.


Nicely said. I'm off to Texas on the first pull.


Thanks for the info.
 
#20 ·
Hey Captainmal,


How about some close up pictures of the fuel system on your engine. Is there a FICM and is it cooled by the fuel? I would be curious considering GM said they were worried about lift pumps damaging the FICM. I'm not sure who the designer of the FICM would be; the vehicle manufacturer or Bosch?
 
#23 ·
Hey, I gotta say this, I have driven all three of these trucks as my friends/ parents have them. I think for the 99.9 % of us there is not a POS truck out there. If there wasn't competition we wouldn't have the diesels we do today or the trucks for that matter. As for the GM electrial problems, we haven't experience power problems on any of them. My cars battery even lasted 130K miles before I decided it might be smart to replace it. The best truck we had was a company 3/4 86 with a 454, man it lasted on the jobsites for at least 9 years, it was abused more than anyone here could dishout. But, I am comming up on buying one of these three trucks and am in the same jam. But you gotta respect what a person buys, it's their money and their choice.



Lenny
 
#24 ·
MonteCarlo31 said:
Hey, I gotta say this, I have driven all three of these trucks as my friends/ parents have them. I think for the 99.9 % of us there is not a POS truck out there. If there wasn't competition we wouldn't have the diesels we do today or the trucks for that matter. As for the GM electrial problems, we haven't experience power problems on any of them. My cars battery even lasted 130K miles before I decided it might be smart to replace it. The best truck we had was a company 3/4 86 with a 454, man it lasted on the jobsites for at least 9 years, it was abused more than anyone here could dishout. But, I am comming up on buying one of these three trucks and am in the same jam. But you gotta respect what a person buys, it's their money and their choice.



Lenny




I agree. Someone said here or on the page once 'Never bash someones 40k dream truck'. This is a good way to look at it. None of us like being told our trucks are a POS and neither do the Ford or Dodge owners. Reality is that most people are living a life long dream owning these trucks.

They are all good trucks. None are significantly better then another. Each have their stong points and weak points. Edited by: Max Power
 
#25 ·
I'd've bought a D/A 2500HD had the Dodge not been $16,000 cheaper... The Dodge was a 2 years old and 33,000 miles when I bought it for $26,000. I bought it at a Chevrolet Dealer in March of 2001. They had only one Duramax truck there and it was listed for $42,000. I'm glad I bought what I did - I initially just bought an engine, but the rest of the truck has grown on me.
 
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