Honest Comparison - 3500 RAM Cummins vs GMC DMAX

[ArrowsmithPML]

Ok guys (and gals),

I am very likely in need of a second "loaded" work truck this year. Having been a Cummins guy for the last 22 years but since 2017 an owner of a Yukon and as well now a Camaro the way the new GM product is spec'd it has all the bells and whistles but still functions like a truck, minus the solid front axle. Having tested a new 2021 3500 AT4 DMAX - I really like it. I love the upfitter switches, the HUD and the ride is as good or better than my 2012 3500 RAM (which has aftermarket FOX 2.0 shocks and a nice lift). Now for what I do, it still needs to be leveled out as that front lower valance will get ripped off in a week but otherwise, very nice. 

Comparing to a similarly equipped 3500 RAM and honestly, and this is coming from a RAM guy, these aren't even in the same park, let alone field. Sure the Cummins is great but the truck felt a tad cheap and when both are over $100K (CDN) it has to feel right. The other big gripe I have is with that 12" screen. I love tech but if you just want to turn on the seats or something, there are too many screens, too much distraction and frankly as I do a lot of driving at night, even turned down it was too bright and made it hard to see outside.

 

So for this knowledgeable group here are some questions:

1. cost of ownership? this will be a work truck and not a grocery getter so it will do a lot of long hauls but more so, a lot of slow bumpy driving on goat trails. So is the drive line up to the task? I don't want to be getting alignments every other oil change or whatever.

2. V8 DMAX vs I6 Cummins - again cost of ownership? will I get 400,000 km before I need to do anything major with valves, rings etc.?

3. I do a lot of idling (no comments from the greens please) so this must be able to handle that without burning a bunch of fuel (or something might just fall off). EGR? DPF? DEF?

4. I wasn't planning on a shorter than 8 FT box but I really don't need another "barn on wheels" so is this "standard box" good enough?

5. GM 10 speed auto vs the RAM 6 speed auto? The RAM is not all that great but I know how to fix it.

 

Now to throw a wrench in here, I started looking at the 1500 AT4 but quickly found no upfitter switches and it needed a 4" lift kit even though it claims to be taller than a regular sierra - although frankly, that is marginal at best. I though the 6.2L would do me fine with the 10 speed auto but I am concerned about my 10 year 400,000 range I typically consider for replacement but equally thought that I could add a 2.7L super charger to it after the jobs and make my own version of a Hennessy - because I think I could do that.

 

So, thoughts? comments? am I crazy? remember, work truck, long distances, lots of idling and so on...

 

Any help would be greatly appreciated.

[Dunn]

the standard bed is 6'9" vs 6'4" on GM vs Ram......its deeper, wider, and longer....plus has better tie down locations......was HUGE for me in buying a new truck.....idk much about diesels but everything ive read or seen says Dmax and 10spd are flawless....the GM does ride really nice for HD truck....and GM reliabilty is typically better (not always but generally)......Ram does have nice interior for sure and truck is more than capable.....i like 12" screen, layout and storage on Ram but other stuff was more important to me plus I just like the look of GM truck better, and 8" screen is more than enough....Ram front end bugs me, lol.......to each their own, either will do

 

 

 

 

[ArrowsmithPML]

I've the exact opposite with gas engines. Been a diesel guy for nearly 3 decades but now with all the filters and cleaners and this and that, does this push the cost of ownership through the roof. I'm guessing it gets close. I enjoy the GM 8speed in my camaro and my yukon so the 10 should be as good or better. I know it was co-developed with Ford but I just don't like the eco-boost stuff so I am staying away for now.

I like both front ends - no issue, lots of truck there for sure. 

Anyway, not a quick decision.

[Njmurvin]

I owned a 3rd Gen Ram 3500 Cummins for 16 years before trading up to my Duramax 3500. I only had about 100k on the Ram but it left me stranded twice in the last year (once with the fifth wheel connected) and that's not a good feeling. So, my wife insisted we get something new (who am I to argue with THAT?). For me, the jump was significant: from 325hp to 445hp and 600lbft to 910lbft. Yes, this truck is heavier but the towing experience with my 12k lb fifth wheel is a day and night improvement. With the added power and butter-smooth 10speed auto (vs 4-speed 48RE), my Dmax doesn't even breathe hard - even on 6% and higher climbs.

 

Three factors made me decide to get the Dmax last summer: (1) Inventory was low, so Ram dealers wouldn't deal much and incentives were weak at best, (2) the 2019-2020 Ram trucks that were available at that time had the CP4.2 injection pumps (starting with MY2021 models they're going back to the CP3 pump), and (3) I qualified for the GM Family First discount. I found a truck on a dealer lot about 1 hour from me that fit my needs so I pulled the trigger.

 

All things being equal (price, injection pumps and features), I probably would have gone for the Ram HO with Aisin trans just because of my history with Cummins. But I don't regret at all switching to GM. The longer standard bed, roomier crew cab and that Allison transmission are really nice bonuses.  I have no idea which brand will most likely get you to 400,000 km without issues (probably neither). But you're likely to find more high mileage owners over on the Ram forums.

[f8l vnm]

The 5+ inch bed difference is pretty significant if you ask me. Especially in a HD truck 

[Dunn]

1 hour ago, f8l vnm said:

The 5+ inch bed difference is pretty significant if you ask me. Especially in a HD truck 

makes all the difference.....if you use bed alot

[ArrowsmithPML]

Don't get me started on injection issues - that's something they all suffer from as far as I can tell.

I've always had a long box but don't need another as I don't plan on trading the 2012 cummins. 

When I say 400,000km it is because of wear and tear, assuming normal/ regular maintenance. I don't want to be doing valves of injectors or whatever.

My 2012 has done well as I have EFI live on it with a custom tow tune and if it can be done I would likely do that to a new DMAX just because of the idling I do on site in the cold.

Still at $100k this is a hard pill to swallow.

 

[ArrowsmithPML]

1 hour ago, Dunn said:

makes all the difference.....if you use bed alot

Not even close to an 8FT box but...

 

[Dunn]

1 hour ago, ArrowsmithPML said:

Not even close to an 8FT box but...

 

I dont want wheelbase of an 8ft box in CC...too long for beach cities.....I bet in cubic feet its probably pretty close to a Ram 8ft box

[Shawn T]

I have always owned Duramaxes (LB7, LBZ, LML, L5P) and they have been bullet proof, grant it they have been personal, not fleet trucks.  The big thing for me is that GM perfected a diesel motor in 2001 and has stuck with it.  The '21 marks the 21st model year and they are on the 6th revision of the 6.6L Duramax.  The Allison transmission has evolved from a 5 speed, to a 6 speed, and now a 10 speed.  Again, honing perfection.

  I have friends that are died in the wool Power Stroke and Cummins drivers and they both have the same gripe.  When ford went away from the Navistar 7.3L the dependability and maintenance costs went through the roof.  The RAM guys are the same, the 6.7L is nowhere near as dependable as the 5.9L.  

 If something is dependable and long lasting why try to change that, just strive perfect it, as GM has? Look at the Chevy small block, it's living proof.

[ArrowsmithPML]

I don't dispute your comments at all. In fact they are almost exactly as I would have said.

The 6.7L Cummins isn't horrible if the enviro stuff falls off but agreed my 2 older 5.9L were so much better. My powerstroke before that was a 7.3L so again, I agree. I have an uncle that had a first gen 2001 GMC DMAX and put nearly 450,000 km on it with some injector issues and some pump problems but his new 2021 Chevy 3500 DMAX seems to be treating him well, minus a bunch of electrical creature comforts that aren't working properly.

[i82much]

i gotta know what you do for a living that requires hours in an HD diesel truck on a goat trail.  need a good employee?  my job is boring!

[ArrowsmithPML]

Well a little background...

I own a construction management company. Currently my commute is 1,700 km 1 way every 3 weeks. Once on site, it is 120 km a day (minimum) and at least 1 hour of highway driving and 6 hours of slow bumpy kidney buster driving. On a slow month, maybe 1,000 km and on a busy one, much closer to 10,000 km. Oh and did I mention that it was in the bitter cold (-15 to -40C plus heavy winds making that feel like another 10 to 30 lower) most of the time? 

Northern British Columbia, Canada. Enjoy.

www.arrowsmithpm.com

 

[i82much]

23 hours ago, ArrowsmithPML said:

Well a little background...

I own a construction management company. Currently my commute is 1,700 km 1 way every 3 weeks. Once on site, it is 120 km a day (minimum) and at least 1 hour of highway driving and 6 hours of slow bumpy kidney buster driving. On a slow month, maybe 1,000 km and on a busy one, much closer to 10,000 km. Oh and did I mention that it was in the bitter cold (-15 to -40C plus heavy winds making that feel like another 10 to 30 lower) most of the time? 

Northern British Columbia, Canada. Enjoy.

www.arrowsmithpm.com

 

very cool. 

[20gmctruckguy]

My vote would be for a GM. I know of a couple guys around here that have Rams and are not very happy with them. Also, if you do a lot of slow bumpy driving, nothing rides better on a rough road than a long wheel base. Let some air out of the tires and it will help too. 

I was wondering about that huge screen in the Ram. Thought it might be a bit distracting.

Edited January 18, 2021 by 20gmctruckguy