HD Diesel Truck Owners Know This

[maxxtc]

Originally Posted by RFSims

Back in Sept 2019 I bought a GMC 2500 HD Denali Duramax to tow my 2018 Rockwood 2902WS travel trailer. Trailer is 33'9" length and around 7500-8000lbs loaded. Fastway E2 1000/10,000lb hitch. 1/3 tank of fresh water, 200lb in the truck bed.

A post surgical back issue and Covid delayed any extended trip. Wife and I just finished a 1720 mile trip from central Arkansas to Smoky Mountain National park area. I pull the trailer at 65mph ( hit 80 once), Tow mode/ cruise control on. The truck goes up the hills at 65mph, goes down the hills at 65 mph and rarely shifts out of 6th gear. Motor turning a quiet 1550rpms that can not be heard in the cab. Truck descended a 4 mile 4% grade and only gained 1 mph to 66. Exhaust brake was not engaged. Ascended a 5.24% grade at 65 mph and did not shift out of 6th gear. No sway or wiggle at any time.

Wife said the ride was more comfortable than her 2018 Cadillac XT5.

My point is, if you can afford a HD Diesel of your favorite flavor, towing large travel trailers is an enjoyable experience. Oh yea, my towing mpg was 12mpg.

Forget the payload stickers and CAT scales and buy a HD diesel truck. You can thank me later.

I have owned Caddy's since my 2nd year of college and I'm 63 now and have owned heavy duty trucks too as I also farmed. Now that I'm semi-retired and rent my land out I'm on the road and nothing rides better than a Cadillac

[KnP]

I came across a video about the F450.and 2500HD that cross check what the dealer told me. The difference between the 3500 and 2500 is the suspension, the rest is identical as far the powertrain and chassis. In theory, both trucks are almost 98% identical.

On the video that I found was based on some kind of DOT classification. What is said on the video is the limit for the class without a CDL is 25,000lbs combine weight of Truck, Cargo and Trailer. The F450 is so heavy, that leaves no room for usable cargo. So Ford, downrated a heavy truck with no much room to spare. GM in another hand, made the 2500 beefier and placed it close to the 3500 class of the 25,000 lbs limit.

I can vouch for that, the 6.6 DMax mated with the Allison 10 speed is a bad boy. Cannot believe how it pulls my 5th wheel and keep up with traffic Might catch flack for this, but the new DMax is as good as the Cummins. Have anybody seen the series with Gale Banks about on "How To Kill a Duramax". He was able to squeeze with bone stock internals some around 905HPs and over 1,000 ft/lbs torque and not even stressing the motor.

[koko 3052]

Originally Posted by RFSims

Back in Sept 2019 I bought a GMC 2500 HD Denali Duramax to tow my 2018 Rockwood 2902WS travel trailer. Trailer is 33'9" length and around 7500-8000lbs loaded. Fastway E2 1000/10,000lb hitch. 1/3 tank of fresh water, 200lb in the truck bed.

A post surgical back issue and Covid delayed any extended trip. Wife and I just finished a 1720 mile trip from central Arkansas to Smoky Mountain National park area. I pull the trailer at 65mph ( hit 80 once), Tow mode/ cruise control on. The truck goes up the hills at 65mph, goes down the hills at 65 mph and rarely shifts out of 6th gear. Motor turning a quiet 1550rpms that can not be heard in the cab. Truck descended a 4 mile 4% grade and only gained 1 mph to 66. Exhaust brake was not engaged. Ascended a 5.24% grade at 65 mph and did not shift out of 6th gear. No sway or wiggle at any time.

Wife said the ride was more comfortable than her 2018 Cadillac XT5.

My point is, if you can afford a HD Diesel of your favorite flavor, towing large travel trailers is an enjoyable experience. Oh yea, my towing mpg was 12mpg.

Forget the payload stickers and CAT scales and buy a HD diesel truck. You can thank me later.

I have the same truck & pull a little bigger trailer...PLEASED AS PUNCH! Great power, great handling, great fuel mileage!

[tomaziegler]

In 2017, I purchased my 2500 HD Duramax in anticipation of buying that “retirement” RV in next few years. Of Course that same year, we found a “deal” on our Cedar Creek 36CK2.
40.5’ long. It was a year for firsts (ie. first 2500, first diesel, first 5th wheel and hitch). To say I was bit intimidated would be an understatement. Having said that, my DW and I both say that rolling down the expressway fully loaded is probably the smoothest that truck ever feels. The “sweet spot” seems to be about 62 mph. Sure I can pull faster, but why? The point, fully loaded ride is extremely smooth compared to running around town in empty truck on these horrible Michigan roads! Love my truck! One of my better decisions

[Bobh1]

Totally agree with upgrading tires. To me it is the single most important upgrade one can do. It is a fact that trucks ride rougher than automobiles. If you can't deal with that then take your cadillac and stay at the Hampton. Tires are what is between you and the road. I always replace stock tires AND rims with aftermarket wider and stiffer sidewall tires. Better stance and stability.
On the subject of DEF......
It is used to "clean" the exhaust of diesel engines. Federal government mandated it "thank you very much". Made my costs as a truckdriver, delivering produce across the country, rise and added an expensive maintenance item to deal with. The harder the engine works the more DEF is used.
Lastly, diesels are made for pulling. Not that gas cannot do the same, diesels just do it better. This coming from real world experiences.
Let the bashing begin.......

[Bhrava]

I noticed the same thing when I pulled our last trailer. For 3 years towed it with an F150, which did the job well, no complaints once the setup was correct. Towed the same trailer with an F350 and it was like there was no trailer back there. Also went from 8 MPG to 13 MPG. Still needed the WDH for sway control, but that should be done on any trailer the size of a billboard.

Now with a 5th wheel, the ride is even better, though the MPG did go to 11. I just finished up installing a Disaster Prevention Kit, which required the removal of the upper and lower intakes. Once I got them off I saw why people hate EGR on diesel, what a cruddy mess!!!! Now that I cleaned out a couple pounds of crud and enlarged the intake by at least an inch, as well as cleaned 1/4" of crud off the back of the EGR butterfly, which no longer operates, wink wink, nudge nudge, it might get better MPG, it will have more power at the very least now that it can fully breath again.

This DEF stuff people talk about, never used it. My truck came pre-deleted from the dealer.

[cbcg710]

I basically have the same setup, but my TT may weight a little more…and I agree 💯%. I never thought I would own a diesel, but I’m currently in my 2nd GMC 2500HD. And I love the Fastway Equalizer hitch. I’ve always debated using my cruise control when towing. Stay safe in your travels!!!

[Qwkynuf]

Originally Posted by Bhrava

I noticed the same thing when I pulled our last trailer. For 3 years towed it with an F150, which did the job well, no complaints once the setup was correct. Towed the same trailer with an F350 and it was like there was no trailer back there. Also went from 8 MPG to 13 MPG. Still needed the WDH for sway control, but that should be done on any trailer the size of a billboard.

Now with a 5th wheel, the ride is even better, though the MPG did go to 11. I just finished up installing a Disaster Prevention Kit, which required the removal of the upper and lower intakes. Once I got them off I saw why people hate EGR on diesel, what a cruddy mess!!!! Now that I cleaned out a couple pounds of crud and enlarged the intake by at least an inch, as well as cleaned 1/4" of crud off the back of the EGR butterfly, which no longer operates, wink wink, nudge nudge, it might get better MPG, it will have more power at the very least now that it can fully breath again.

This DEF stuff people talk about, never used it. My truck came pre-deleted from the dealer.

Everybody wants clean air - we just want somebody else to provide it, so that we don't have to be inconvenienced.

[Jim34RL]

Originally Posted by Mandog

Hmm my cousins is an 08 with the 5.9. Kinda weird. They are great motors and easy to work on.....

I would like to see that since Dodge switched all production to the 6.7L Cummins engine with the 6 spd auto 68RFE transmission in Jan. of 2007. That is why there is a 2007.5 model year production differential between the early 2007, 5.9L Cummins truck. Take a pic of the engine most 6.7L users can tell the difference right away between the 5.9L and the 6.7L engines in a Dodge truck!

Now if there is a 5.9L Cummins in a motorhome built in 2008 that is entirely possible. Since engines are produced much earlier in the build cycle with engines being stockpile by the motorhome producer until needed.

[Bhrava]

Who's to say burning horse urine doesn't pollute or spew other unknown chemicals into the air? Remember when California, the state of everything being cancerous, decided to mandate the use of MTBE in gasoline to replace lead? Turned out to be a not so good thing since it contaminated all the soils.

For the record, I didn't buy the truck because it was deleted, I didn't even know it was deleted until a few weeks later, and I would not delete it if it were whole. I can see why people remove the EGR though, what a mess!

[Jim34RL]

Originally Posted by KnP

On the video that I found was based on some kind of DOT classification. What is said on the video is the limit for the class without a CDL is 25,000lbs combine weight of Truck, Cargo and Trailer. The F450 is so heavy, that leaves no room for usable cargo. So Ford, downrated a heavy truck with no much room to spare. GM in another hand, made the 2500 beefier and placed it close to the 3500 class of the 25,000 lbs limit.

That is incorrect the limit is 26,001LBS. If you are over 26,001 LBS than you will need a non-commercial driver licenses (Class A or B in IL) that allows you to legally operate at the heavier weights.

[Dan50]

Originally Posted by Jim34RL

No; you do not need to know the payload numbers that is only important to the weight police!

What is required for you to know is the Gross Combined Weight Rating and the Gross Rear Axle weight numbers of your truck. I also look at tire loading for my needs on my truck. My 3/4 ton Dodge Mega Cab 6.7L Cummins, pulling my 34RL Cedar Creek is under the rear axle loading weight and the Gross Combined weight rating for my truck. I have run across a cat scale to confirm this information.

Yes, by all means, ignore the number ratings you don't meet and laud the ones that you do. I mean, after all, you know more about the weight carrying capabilities than the manufacturer right? Such an old story.

[Bobh1]

Originally Posted by qwkynuf

everybody wants clean air - we just want somebody else to provide it, so that we don't have to be inconvenienced.

if you bought it
a truck brought it!

[NMWildcat]

Originally Posted by Dan50

Yes, by all means, ignore the number ratings you don't meet and laud the ones that you do. I mean, after all, you know more about the weight carrying capabilities than the manufacturer right? Such an old story.

You know where the manufacturers get those numbers right? They are a compromise between engineers, lawyers, sales, and marketing. But by all means, you should take them as gospel and arrange your life accordingly.
I'll stick with real life experience like Jim34RL and take those numbers for what they are... Suggestions.

[Bogieboy]

Originally Posted by aceinspp

I'm glad you all like your diesels and DEF issues. Enjoy. A gas lover. Later RJD

we got a diesel with no def or dpf to worry about.... enjoy your crummy towing mpg......LOL

[NMWildcat]

Originally Posted by Bogieboy

we got a diesel with no def or dpf to worry about.... enjoy your crummy towing mpg......LOL

Actually, anybody who brags about mpg while towing an RV with anything is just laughable.

[5er_tom]

Towing MPG is just a curiosity number. If you take it seriously, and it worries you, you are participating in the wrong sport.

Go wind surfing.

[DouglasReid]

Originally Posted by Beachbourbon

Not a blanket statement, make model year specific. My RAM 3500 has a the HO Cummins and the Aisin transmission and it is my understanding these are not available on the 2500, so not just additional springs on the suspension when upgrading to a 3500. I’m sure there are many more differences I haven’t noticed, but don’t really care because I’m not trying to make my truck into something it’s not, like gerryrigging a 2500 to say it can function like a 3500.

That Aisin Transmission is a Very good one in fact is is a copy of the Allison. So close a copy in fact that Allison sued Aisin and won, Aisin pays Allison for EVERY transmission they make.

It is available as a special order on the 2500s, but it is a VERY expensive upgrade because of those payments to Allison.

[DouglasReid]

Originally Posted by 01tundra

FYI - I believe this was true up to 2019.

According to a guy who is an engineer for GM over on the Duramax forum starting in 2020 the 2500HD has a 11.5" ring gear and the 3500 has a 12" gear. There's also torque limiting in 1st gear for the 2500 that isn't present in the 3500 due to the larger ring gear.

From what I've read, starting in 2020 the 3500 uses a Rockwell rear axle, whereas the 2500 utilizes a Dana.

GM agrees with him -

https://www.gmc.com/gmc-life/trucks/...rra-heavy-duty

I knew they made some changes in the later year models. In my sig you see I drive an 08 2500.

Id LOVE to have that new 10 speed xmsn but at the price of a new truck I cannot justify it to myself since this one still is doing just what I want it to do.

[DouglasReid]

Originally Posted by BigH

As a blanket statement it is absolutely false. It is true for some configurations but not all. Some time ago (years maybe) I posted a link showing your statement to be false.


It wasn't true before 2019 either.

Congratulations, you will the "Politician of the Thread" award ...............NOT a compliment I might add.

Lots of words, none of which are Absolutely Helpful to anyone.

Mostly negative words bashing anyone you think you should disagree with