Forum Discussion
- I found this pretty interesting. I have been looking into new trucks and had talked myself into waiting until GM released the rumored 850 foot/pounds Dmax. However after a weekend of internet researching. I don't know if it is that big of deal except to satisfy my Type A mentality which is to have the most powerful Dmax available (without mods). I am seriously considering going 3500 SRW this time. I compared the specs from Ram and Ford, and than Utube videos of these pull off comparo's. It does not appear to me that the 850 ft/pnds buys anything in the real world. The tow ratings with 3.73 or similar ratios are much the same across the big three. What sold me, was noticing that on the Ford and Ram, that they will give the 30K tow rating to a 3500 but when it comes to the 45/5500 trucks it comes back down to the mid 20's. I know the power outputs are derated, I cant recall tow ratings being derated as well, but it is evident that the 30K tow rating is only for bragging rights, and the trucks cant live at that duty cycle for long or they would maintain that rating in the heavier trucks. Ultimately the Dmax has to have equal power to the other two to prevent getting slaughtered in the truck ads, but at the end of the day, when the 765 foot/pnd engine can do this well, I don't think it will improve towing performance in any significant way to increase the power. Combined with the fact that GM has been building this version of the Dmax since 2011, I think they have it pretty well figured out, that may not be the case with the 850 version.
I would like to also know the ambient air temp as well as coolant and tranny temp of the these trucks when they reach the top. That to me tells me more about the capacity of the pickup than does speed/time up the hill alone. - It's been a couple of years but, it was brought up about how Ford and Dodge came up with their power numbers vs. GM.
GM was the ONLY one to rate the power by the stringent SAE method.
I forget the particulars, but basically think peak vs. continuous power. That explains how a lower rated truck such as the GM can win these contests. - I think also the GM rep claimed in that earlier Canadian tow-off article that GM does a better job of torque management, getting the torque to the ground. He claimed that torque at the wheels, not at the engine was where GM excelled.
Whatever, they all look good to me. Would love to have new one, but the initial price, complexity of the emissions system, quality of diesel fuel vs fuel pump issues ... maybe in a few years when I'm looking for a new truck things will be different. brulaz wrote:
I think also the GM rep claimed in that earlier Canadian tow-off article that GM does a better job of torque management, getting the torque to the ground. He claimed that torque at the wheels, not at the engine was where GM excelled.
Whatever, they all look good to me. Would love to have new one, but the initial price, complexity of the emissions system, quality of diesel fuel vs fuel pump issues ... maybe in a few years when I'm looking for a new truck things will be different.
Agreed on both points.
When I was truck shopping a few months ago, I drove a new RAM 3500 with the 850tq Cummins. Floored from a dead stop, I wasn't impressed - given the 850tq rating I was expecting more. My mildly tuned 5.9L Cummins would have walked away from it -- especially off the line. I don't know for sure, but I think the huge tq numbers have to be cut at the knees in the lower gears to prevent parts breakage. It sure felt like it to my butt dyno anyway.
I know they all (Ford GM RAM) tq manage to some extent, but despite being way down on power (on paper) the Duramax isn't left as far behind as one would think given the huge disparity in the advertised numbers.
I do think GM is going to be forced to bump up the power in the next model year as they are pretty far behind for advertising bragging rights.
The only thing I absolutely can't wrap my head around when it comes to the GM Duramax is that dang DEF tank hanging down just waiting to be knocked off by a chunk of ice, rock, etc. They really need to rethink that placement.- I also think it is possible that GM is underrating these engines a little bit. I saw a company, I think it was Alligator Performance, that had run a 2015 on the dyno and stock the numbers were really good! Like almost what GM claimed for HP and Torque, but at the rear wheels.
ksss wrote:
I would like to also know the ambient air temp as well as coolant and tranny temp of the these trucks when they reach the top. That to me tells me more about the capacity of the pickup than does speed/time up the hill alone.
Exactly. The video lacked those kinds of details which I was wanting to know.ib516 wrote:
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I do think GM is going to be forced to bump up the power in the next model year as they are pretty far behind for advertising bragging rights.
You are right, but it's so stupid really.
The only thing I absolutely can't wrap my head around when it comes to the GM Duramax is that dang DEF tank hanging down just waiting to be knocked off by a chunk of ice, rock, etc. They really need to rethink that placement.
Heh, exactly my thought when I first saw it. And it's so exposed to the cold, doesn't DEF freeze? or do they have anti-freeze for it?- Yes DEF is mostly water so it freezes. All the 2500/3500 diesel trucks from the big 3 have heated DEF tanks (more complexity).
- Like others have posted, the focus should have been on temperatures generated instead of speed. I'm perfectly happy coming in behind the pack knowing I can continue on without heat or mechanical issues in my older 6.0 PSD that everyone loves to hate. I have been lucky that reliability has been a strong point of my truck (even if some think it is an enigma) while still giving me sufficient power to climb hills under load comfortably all while being 100% stock.
The emissions complexity and initial cost of current diesels is swaying me toward a gasoline engine in my next truck even though I love diesels. The push has been for ever increasing performance without efficiency gains which also drives up operating costs. I think it's pretty sad when a diesel diehard is looking to abandon the technology due to the direction the manufacturers and marketing are pointed. ib516 wrote:
ksss wrote:
I would like to also know the ambient air temp as well as coolant and tranny temp of the these trucks when they reach the top. That to me tells me more about the capacity of the pickup than does speed/time up the hill alone.
Exactly. The video lacked those kinds of details which I was wanting to know.
There is a reason they did this where they did this and when they did this. I would bet money it was no accident there was snow around when they did this test.
There was a reason they did not do this test on a 105 degree day on the Cajon pass.
There is a reason boats with the same engine as trucks are rated at a way higher HP and way higher duty cycle.
It's easy to make any HP you want. It's extremely difficult to handle the thermal load for that high HP. Ever see the fan or radiator size on a 6.7 Ford, 6.7 Dodge or 6.6 Chevy? :E
