New to GM diesel

Mike Weinandy · December 11, 2023

I'm picking up a gmc dually diesel layer this week. I started in Chevys back in 1995 and switched to Ford in 2008 when I couldn't find a Chevy because of the bailout. 15 years later I'm back to GM because Ford can't make a truck. I'm looking forward to it - I still have a Ford on order if they ever make it. I'm looking for any suggestions or advice.

1. What kind of mileage should I expect?

2. Def usage?

3. Easy to use tech?

I'm coming from a 2021 Ford diesel. I didn't want to switch but I change every 3 years and I've waited over a year for a new Ford with no end in sight. Thanks for the help!

Edited December 13, 2023 by Mike Weinandy
To long

Dunn · December 12, 2023

this is best forum for chevy or GM trucks

Pryme · December 12, 2023

9 hours ago, Dunn said:

this is best forum for chevy or GM trucks

And it’s the only forum I’ve been on with a group of adults acting like adults. And I’ve been visiting forums since 2000.

browsing ford truck forums you would think it’s a highschool detention center.

but I almost never leave this HD sub forum.

Joel Crow · December 13, 2023

On 12/10/2023 at 7:16 PM, Mike Weinandy said:

I'm picking up a gmc dually diesel layer this week. I started in Chevys back in 1995 and switched to Ford in 2008 when I couldn't find a Chevy because of the bailout. 15 years later I'm back to GM because Ford can't make a truck. I'm looking forward to it - I still have a Ford on order if they ever make it. I'm looking for any suggestions or advice.

1. What kind of mileage should I expect?

2. Def usage?

3. Easy to use tech?

I'm coming from a 2021 Ford diesel. I didn't want to switch but I change every 3 years and I've waited over a year for a new Ford with no end in sight. Thanks for the help!

I'm excited to hear what you find / feel / experience as a GM user from the good old days when they made 300k mile trucks with comfy couch seats that lasted forever. I'm new to diesel and in the market for an HD to pull a big enough RV for my wife to join me :). If no one responds to you before, please still come back and share your thoughts for the rest of us (forum lurkers) who would appreciate real-people feedback!

I test drove a 2024 LT HD 2500 (Gas) today and can tell you she's a very professional feeling machine, a lot bigger than I expected (I owned two 1500s from 08-13) and obviously capable to pull. I'm in the market for the "High Costry" Diesel 2500... which is hard to find in a dealer parking lot near me. Thanks for any feedback you can share on your dually, and congratulations!

Edited December 13, 2023 by Joel Crow

Mike Weinandy · December 14, 2023

I'm looking forward to it. Last Chevy diesel was a 2005 duramax. No pollution controls. That was a good engine. It took till the last couple years to get them close to what they were 18 years ago. I'm still keeping my Ford on order - I can always switch back if things don't work out. That's if Ford can make a truck

Dunn · December 14, 2023

11 hours ago, Joel Crow said:

I'm excited to hear what you find / feel / experience as a GM user from the good old days when they made 300k mile trucks with comfy couch seats that lasted forever. I'm new to diesel and in the market for an HD to pull a big enough RV for my wife to join me :). If no one responds to you before, please still come back and share your thoughts for the rest of us (forum lurkers) who would appreciate real-people feedback!

I test drove a 2024 LT HD 2500 (Gas) today and can tell you she's a very professional feeling machine, a lot bigger than I expected (I owned two 1500s from 08-13) and obviously capable to pull. I'm in the market for the "High Costry" Diesel 2500... which is hard to find in a dealer parking lot near me. Thanks for any feedback you can share on your dually, and congratulations!

seen quite a few H.C. out west, idk where you are though

nitro882 · December 25, 2023

On 12/10/2023 at 7:16 PM, Mike Weinandy said:

I'm picking up a gmc dually diesel layer this week. I started in Chevys back in 1995 and switched to Ford in 2008 when I couldn't find a Chevy because of the bailout. 15 years later I'm back to GM because Ford can't make a truck. I'm looking forward to it - I still have a Ford on order if they ever make it. I'm looking for any suggestions or advice.

1. What kind of mileage should I expect?

2. Def usage?

3. Easy to use tech?

I'm coming from a 2021 Ford diesel. I didn't want to switch but I change every 3 years and I've waited over a year for a new Ford with no end in sight. Thanks for the help!

I think on the fuel economy question there is a LOT of variables there. Terrain, cargo, driving style etc can all play a big role in what you get. That said here is how mine has been. In Florida where i live its pretty flat and on a straight freeway trip unloaded i can see as much as 22mpg out of my Denali DRW. City is like 13ish for me. Towing my 5th wheel im getting 8-9.5 depending on terrain. We just picked up a new DRV a little over a week ago which weighs 24 k loaded and i got 8 going thru the smokies on the way back to Florida and as the ground got flatter the mileage went up. The truck can pull tho, that i can confirm. I did not want for more power for sure even up some of the 7% grades.

Def usage. I have like 9k on my truck now and ive filled the tank twice in that time. I just filled it at the pump in Sevierville TN last week and towed my RV about 700 miles back to Florida and it moved 1 bar on the gauge. Given that my first tank of def lasted like 6000 miles i wont be filling it for a long time. I dont know if this is good or bad useage since this is my first diesel truck but it seems like it does not use much to me.

Tech seems plenty easy to use but thats a subjective thing. I am a computer networking engineer so tech comes easy to me.

One suggestion i have is a Banks idash. GM did not do the best job on the gauge package and its nice to know how close you are to a regen and stuff like that. I find GM is pretty aggressive with the regen on this truck. Unloaded im doing a regen about every 200 miles or so which seems like a lot. With the RV its tow its like 600.

Edited December 25, 2023 by nitro882

gregus73 · December 25, 2023

The only Ford that I owned was a late 90s Ranger in my 20s. Cannot compare much against Fords.

Very pleased with the Duramax. It gets decent mpg for the size of the vehicle…for me it is about 19 mpg give or take.

The 2024 2500 is really quick too. GM added extra hp and torque for 2024.

I keep 2 boxes of def fluid at my condo and my cabin. I find that I add def fluid every 1000 miles or so.

I love the tech and how easy it is to use on the 2024. The Google interface is a huge improvement over the past infotainment GUI.

The most difficult tech that I found is on my wife’s Lexus or Macan S that I had for a brief while. Really prefer the gui on the GM products.

Edited December 25, 2023 by gregus73

Joel Crow · December 25, 2023

I am very excited (and much, much, poorer) to announce that I just purchased a 2024 GMC Denali 2500 HD with the Diesel engine... Picking her up tomorrow!

We ALSO purchased a Brinkley Z3100 5th wheel this weekend as well.

So everyone is about to join me on a learning journey with both my first diesel as well as first RV. Prayers appreciated!

Merry Christmas!

Joel

gregus73 · December 25, 2023

Beautiful looking truck and trailer, congratulations.

the8rotor · December 26, 2023

Congrats @Joel Crow! Enjoy the new rig and trailer.

nitro882 · December 26, 2023

23 hours ago, Joel Crow said:

I am very excited (and much, much, poorer) to announce that I just purchased a 2024 GMC Denali 2500 HD with the Diesel engine... Picking her up tomorrow!

We ALSO purchased a Brinkley Z3100 5th wheel this weekend as well.

So everyone is about to join me on a learning journey with both my first diesel as well as first RV. Prayers appreciated!

Merry Christmas!

Joel

Congrats on the new RV and truck. What are your plans for the RV? Are you going full time? Where do you plan on going?

We just got our first 5th wheel last week and have moved into it full time. At 46' Its by far the longest thing i have ever towed but im taking it easy and doing ok with it. If there is one piece of advice i can give, If there are any doubts just stop and have your wife spot for you, a set of walkie talkies is a good idea as well and will really help a lot. There have already been a couple times where i could not see what i needed to and had to have my wife spot, the first day we were pulling into a harvest hosts at dusk and i could not see the right wheels well when taking a right hand turn. If i didn't stop and have her spot it i would have run the tires into a 2' deep drainage ditch that in my mirror looked like flat grass. Also needed it on the right rear when pulling out of a pull thru spot a couple days later. The park was tight and having spotter there to watch the right cornet making sure i didn't take out the light post was a good thing since there was no way i could see it.

Here is a shot of my new rig.

Edited December 26, 2023 by nitro882

Kerry Pulaski · January 11, 2024

That is quite a sweet rig, and color combo. Happy to be back into the Duramax, '24 Denali-U, 2500HD. I put in a ScanGauge III, as the gash gauges are lacking. Use it for work, but restored, upgraded and modified the xxxx out of a '73 26ft. GMC Motorhome. That club is also like a cult, of owner's helping owners. Till '76, these had an Old's 455ci front wheel drive ('77-'78 then a 403), 4 wheel independent rear air suspension. One owner replaced the 455 with a Duramax ! That must cruise !!

Next mod is a Limited Slip for the Front Diff., as it is Front Wheel Drive only, and 4 wheel rear disc brakes (now that a kit includes an electric parking brake caliper). When retirement arrives, going down the Smokey Mountains Blue Ridge Pkwy., and all other National Parks as I can.

Enjoy your travels !!

Pryme · January 11, 2024

3 minutes ago, Kerry Pulaski said:

That is quite a sweet rig, and color combo. Happy to be back into the Duramax, '24 Denali-U, 2500HD. I put in a ScanGauge III, as the gash gauges are lacking. Use it for work, but restored, upgraded and modified the xxxx out of a '73 26ft. GMC Motorhome. That club is also like a cult, of owner's helping owners. Till '76, these had an Old's 455ci front wheel drive ('77-'78 then a 403), 4 wheel independent rear air suspension. One owner replaced the 455 with a Duramax ! That must cruise !!

Next mod is a Limited Slip for the Front Diff., as it is Front Wheel Drive only, and 4 wheel rear disc brakes (now that a kit includes an electric parking brake caliper). When retirement arrives, going down the Smokey Mountains Blue Ridge Pkwy., and all other National Parks as I can.

Enjoy your travels !!

That looks awesome. It instantly reminded me of my grandparents old airstream (color) they had when I was younger.