Duramax vs. Cummins- Need some feedback

Gordie Kissner · 12-19-2008, 09:54 PM

I've towed a bunch of miles with both and would take the Cummins over the Duramax everytime especially for durability..As far as automatics go the allison is as good as it gets(though not indestructable),Dodge's automatic is definately better than it used to be with the exhaust brake etc..and the 6-spd manuals are both comparable. The other differences between the two would be a toss up IMO.

Shawn Blair · 12-20-2008, 03:52 AM

Dodge,Cummins,6-speed,Mileage,it's really an easy choice. Besides do you really want to buy an Izusu engine?

james schaechter · 12-20-2008, 08:11 AM

I have a 2002 GMC Duramax 6 speed manual 4 x4 crew cab 2500hd. I have 192k on it. The injectors were all replaced under warranty and the dual mass flywheel was replaced a couple of times under warranty. I love the truck. In the summer, I get up to 24 hwy empty with 3.73 gears and always over 20. In the winter about 2 less mpg avg. Towing I can count on 15 with a 24 ft tag going 75. No mods or programmers.

The only complaint is with the flywheel. GM screwed that deal up and added a healthy dose of CYA when I found out the new improved flywheel was the same junk and would not hold up. There is a fix and it works great. A single mass flywheel. I did that at 110k and have had no issues with that. If you look for a GM stick Duramax, if it still has a dual mass flywheel. Figure in 1200. for the southbend kit if youinstall it yourself and you will be good to go.

Other than that, I plan on going to 300k before I think of getting a newer one. By the way, I would stay away from any of the diesels with the DPF. I think that is 2008 and newer. MPG suffers and I just don't think that is the best way to control the emmissions.

Ed Wright · 12-20-2008, 05:12 PM

James is correct about the DPF, except that started in mid 2007 for the Duramax. That thing and it's calibration, is a mileage killer. The '06 is the last year to for sure avoid that thing. You can buy an "off-road" exhaust system to get rid of it, but it is illegal as hell. If, however, somebody installs the off-road exhaust system, I (and others) have a nice running calibration for them. Off-road use only, you understand. If you plan to buy a programmer for one, be advised the '07 & later Duramax computers store the checksums and CVN numbers (Just another, redudent checksum) for the last ten calibrations that have been loaded. I have heard guys say "I'll just program it back to stock ten times with my hand-held before I go in for warantee Work". That won't get it, as it only stores one copy of a given set of checksums and CVNs. Only way around it would be to buy a spare computer, and lay the original aside to be installed before taking it back to the dealership. Of course, if you have changed to the off-road exhaust your warantee is gone anyway. Some of these "tuners" and popular hand-helds get carried away with power increases. You can make crazy power increases with a diesel, but it tears stuff up. No reason to expect GM to cover that, but some try to slide that by anyway. All I'll do to them is 60 to 75 hp at the tires and 1 to 1.5 mpg. I'll let the other guys make 200+ more hp and tear things up.

Rob Petrie E395 · 12-20-2008, 07:14 PM

On the warranty deal and using a programmer. Buy a clutch from Napa, Carquest, Federated, ect and you will find the first thing you see when you open the box is a paper stating that if the engine tuning has been modifed there is no warranty on their product. I agree with Ed alot of these trucks are tuned up way too far I have seen some that sound like a Peterbuilt with with 6" stacks and smoke like a freight train

Run to Rund · 12-21-2008, 02:16 PM

5th gear goes out on the New Venture 4500 5-speeds. the fix is at www.standardtransmission.com

For lots on the Cummins/Dodge, see www.turbodieselregister.com

For clutches, www.southbendclutch.com and talk to Peter.

Troy Henderson · 12-22-2008, 09:57 AM

2002 3/4 ton Duramax. Bought it in the spring with 76,xxx miles on it. Had the injectors replaced at 65,xxx. Its got 94,xxx on it now. Most of them were from towing a 28' tag at 10,000 lbs. I put a Banks programmer on it with exhaust and K & N filter I bought off ebay used. I also run some Bio Diesel in it. Its impressive. It pulls the hills here in the midwest w/o clicking out of overdrive. Low teens towing 70mph.

I took it to the track here on t&t night and let the fiance drive it. Was running low 14's with a 2.5 sec short time

12-19-2008, 09:54 PM	#1
Gordie Kissner Member Join Date: Oct 2008 Location: Emmett, Idaho Posts: 221 Likes: 1,359 Liked 18 Times in 10 Posts	Re: Duramax vs. Cummins- Need some feedback I've towed a bunch of miles with both and would take the Cummins over the Duramax everytime especially for durability..As far as automatics go the allison is as good as it gets(though not indestructable),Dodge's automatic is definately better than it used to be with the exhaust brake etc..and the 6-spd manuals are both comparable. The other differences between the two would be a toss up IMO.

12-20-2008, 03:52 AM	#2
Shawn Blair Member Join Date: Dec 2007 Location: Everson, WA. Posts: 122 Likes: 1 Liked 0 Times in 0 Posts	Re: Duramax vs. Cummins- Need some feedback Dodge,Cummins,6-speed,Mileage,it's really an easy choice. Besides do you really want to buy an Izusu engine? __________________ Shawn Blair 6383 SS 634 STK

12-20-2008, 08:11 AM	#3
james schaechter VIP Member Join Date: Dec 2004 Location: Cumming GA Posts: 1,994 Likes: 1,299 Liked 1,440 Times in 301 Posts	Re: Duramax vs. Cummins- Need some feedback I have a 2002 GMC Duramax 6 speed manual 4 x4 crew cab 2500hd. I have 192k on it. The injectors were all replaced under warranty and the dual mass flywheel was replaced a couple of times under warranty. I love the truck. In the summer, I get up to 24 hwy empty with 3.73 gears and always over 20. In the winter about 2 less mpg avg. Towing I can count on 15 with a 24 ft tag going 75. No mods or programmers. The only complaint is with the flywheel. GM screwed that deal up and added a healthy dose of CYA when I found out the new improved flywheel was the same junk and would not hold up. There is a fix and it works great. A single mass flywheel. I did that at 110k and have had no issues with that. If you look for a GM stick Duramax, if it still has a dual mass flywheel. Figure in 1200. for the southbend kit if youinstall it yourself and you will be good to go. Other than that, I plan on going to 300k before I think of getting a newer one. By the way, I would stay away from any of the diesels with the DPF. I think that is 2008 and newer. MPG suffers and I just don't think that is the best way to control the emmissions. __________________ James Schaechter 3163 STK

12-20-2008, 05:12 PM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Duramax vs. Cummins- Need some feedback James is correct about the DPF, except that started in mid 2007 for the Duramax. That thing and it's calibration, is a mileage killer. The '06 is the last year to for sure avoid that thing. You can buy an "off-road" exhaust system to get rid of it, but it is illegal as hell. If, however, somebody installs the off-road exhaust system, I (and others) have a nice running calibration for them. Off-road use only, you understand. If you plan to buy a programmer for one, be advised the '07 & later Duramax computers store the checksums and CVN numbers (Just another, redudent checksum) for the last ten calibrations that have been loaded. I have heard guys say "I'll just program it back to stock ten times with my hand-held before I go in for warantee Work". That won't get it, as it only stores one copy of a given set of checksums and CVNs. Only way around it would be to buy a spare computer, and lay the original aside to be installed before taking it back to the dealership. Of course, if you have changed to the off-road exhaust your warantee is gone anyway. Some of these "tuners" and popular hand-helds get carried away with power increases. You can make crazy power increases with a diesel, but it tears stuff up. No reason to expect GM to cover that, but some try to slide that by anyway. All I'll do to them is 60 to 75 hp at the tires and 1 to 1.5 mpg. I'll let the other guys make 200+ more hp and tear things up. __________________ Ed Wright 4156 SS/JA

12-20-2008, 07:14 PM	#5
Rob Petrie E395 VIP Member Join Date: Dec 2007 Location: Woodlawn IL Posts: 1,092 Likes: 162 Liked 216 Times in 77 Posts	Re: Duramax vs. Cummins- Need some feedback On the warranty deal and using a programmer. Buy a clutch from Napa, Carquest, Federated, ect and you will find the first thing you see when you open the box is a paper stating that if the engine tuning has been modifed there is no warranty on their product. I agree with Ed alot of these trucks are tuned up way too far I have seen some that sound like a Peterbuilt with with 6" stacks and smoke like a freight train Last edited by Rob Petrie E395; 12-20-2008 at 07:19 PM.

12-21-2008, 02:16 PM	#6
Run to Rund Senior Member Join Date: Sep 2007 Location: Henderson, NV Posts: 585 Likes: 9 Liked 54 Times in 27 Posts	Re: Duramax vs. Cummins- Need some feedback 5th gear goes out on the New Venture 4500 5-speeds. the fix is at www.standardtransmission.com For lots on the Cummins/Dodge, see www.turbodieselregister.com For clutches, www.southbendclutch.com and talk to Peter.

12-22-2008, 09:57 AM	#7
Troy Henderson Member Join Date: Jul 2006 Location: Kansas City Posts: 412 Likes: 128 Liked 130 Times in 42 Posts	Re: Duramax vs. Cummins- Need some feedback 2002 3/4 ton Duramax. Bought it in the spring with 76,xxx miles on it. Had the injectors replaced at 65,xxx. Its got 94,xxx on it now. Most of them were from towing a 28' tag at 10,000 lbs. I put a Banks programmer on it with exhaust and K & N filter I bought off ebay used. I also run some Bio Diesel in it. Its impressive. It pulls the hills here in the midwest w/o clicking out of overdrive. Low teens towing 70mph. I took it to the track here on t&t night and let the fiance drive it. Was running low 14's with a 2.5 sec short time __________________ Troy Henderson Henderson Race Shop LLC 816-520-5389 www.hendersonraceshop.com

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