GM Duramax 2500 owners

[renderit]

I just bought my "forever truck" because a deal kinda fell in my lap.

How do you like what you have?

Mileage you get with a 25 or above AS?

Break-in etc for these vehicles?

Any limitations I will have?

Particular likes and dislikes?

This thing feels like a TANK. I hope I will not live to regret it.

[LNBright]

My Sierra is a 1500, so I can’t speak to the HD or the diesel, but I can say this:
I was t-boned recently, my Sierra has been in the shop, and the rental from insurance has been a Ram... and while it’s been an acceptable rental, I’m not digging it or anything, but I can say that, I’ve struggled to find anything I like about it better than my Sierra. Legroom, gearing, height, fan controls, ignition switch vs starter button, shifting.... I’ll be very glad to get my Sierra back.

[renderit]

Had a 1500. Traded it for this monster.

Loved the 1500 but feel much more comfortable with the larger trailer we have on order not having to worry about loading etc.

Probably (99%) we would have been fine, but the old one was STILL valuable as a trade and I felt the 2500 Diesel was a "lifetime" truck as in with maint. and care I probably won't have issues for a huge long time. And I should not have ANY worries on loading etc. with the 25.

I think (after driving it for the last 2 days) I 'opened an egg' with a sledgehammer though. Buyers remorse anyone? But it sure has all the bells and whistles.

This one has the push button start. I will say though the key in my 2014 Sierra Crew sure got hotter than a firecracker in the ignition...

[no_worries]

Originally Posted by renderit

I just bought my "forever truck" because a deal kinda fell in my lap.



How do you like what you have?

I have a 2020 and love it. I’ve not experienced any downsides and there isn’t anything I don’t like.


Mileage you get with a 25 or above AS?

Towing a Classic 33, between 12.5 and 13.5 hwy.


Break-in etc for these vehicles?

There is good guidance in the manuals but I did not tow for the first 2500 miles and then limited speed and inclines for the next 2500 miles. Probably overkill.


Any limitations I will have?

Have not encountered any to date. Turning circle is significantly greater than a 1/2 tonne truck. I always let the truck warm up for at least 5 mins before towing. Install a good bed cover and over bed rack system to maximize storage.


Particular likes and dislikes?

Parking (w/out trailer) takes some getting used to. It’s nice to have plenty of torque for when its needed. Little bit more maintenance than a gas-powered truck but we changed out for a DP motorhome so maintenance is much easier/cheaper.


This thing feels like a TANK. I hope I will not live to regret it.

Some comments above.

[jaybauman]

As a GMC 3500HD owner, I was recently invited by a marketing company to do an in-depth comparison of GMC, Chevy, Ram, and Ford HD trucks. I was asked to comment on aesthetics, comfort, ease-of-entry/exit, interior layout/screens/buttons, etc. The whole process took about 3 hours.

When it comes to interior looks and creature comforts, the GM trucks are about 2 generations behind Ram and Ford.

In terms of having exactly what you want, where you want it, when you want it...I'll go with GM every time. But the biggest factor for me is the independent front suspension on the Sierra & Silverado. This makes for such a better driving experience. I would purchase my Sierra again without hesitation. (That, and I kept hitting my head on the roof when getting in/out of the Ram.)

[wulfraat]

Originally Posted by renderit;

I just bought my "forever truck" because a deal kinda fell in my lap.



How do you like what you have?



Mileage you get with a 25 or above AS?



Break-in etc for these vehicles?



Any limitations I will have?



Particular likes and dislikes?



This thing feels like a TANK. I hope I will not live to regret it.

You didn’t mention what year. I am guessing you got a current generation 2021?

Aside from having an interior that looks like it was built by cavemen I like my 2017 Denali 2500.

I have a heavy foot and get about 11-12mpg towing. I got about 14 on one longer trip of 1000 miles once.

Break in is 500 miles. Change out your oil at 2500 and 5000 miles. Then go to 5000 mile increments there after. Full synthetic devlac.

limitations? None really, aside from the overall size / length of the truck if you are looking for parking.

Likes / dislikes - like the modern L5P duramax. Plenty of power and burns much cleaner than previous generations which is important to me. Dislike the interior design and 1980’s technology. (My other car is a Tesla)

The ride is harsh on my truck and I run lower pressures when not towing per the load rating charts. I moved to BFG KO2 275/65r20 tires recently and it made a surprising difference in softening up and smoothing out the ride.

Enjoy your truck

[Buzzr]

I have had mine for 5 years. It has been relatively trouble-free. Had to replace an oil pressure sending unit ($200) and had the def heater replaced under warranty. I have close to 60,000 miles and wouldn't hesitate to buy another one. The Duramax is now a tried and true engine.

[Skillet]

Looks like others have provided good insight already. I have a 2017, love this truck. The only thing I can add is to join a couple Duramax forums on Facebook or GM oriented sites. You can pick up the threads of what other people are going through and what mechanical issues you may one day face. I have 60 K on mine, towed a fair amount, absolutely love this truck.

[Larry1492]

I traded a 1500 Eco Diesel Ram for a 2020, 2500 duramax. I like the ride better. And just really like the larger truck. The capacity is overkill for my 23’ airstream but I tended to be overloading the ram when I added passengers and gear. The ram got 25mpg empty and 12 when towing and the duramax gets 20mpg empty and 19 towing. It’s just more comfortable towing with the larger truck.

Good luck with your truck, I think it will grow on you.

[foolrushin]

I'm on my second Chev Silverado 2500HD Duramax, first one was a 2003 now have a 2011, and now shopping to replace it. They are a beast truck and parking gets "interesting" in tight parking lots. But, I'm used to it now. We get 11 to 13 mpg towing a FC30RB. Well I get close to 13, my spouse has a heavier foot and then its closer to 11. I tend to agree that GM and Ford should work on their interiors more. Our other car is a BMW X5 xDrive, night and day difference in the interiors, electronics, etc.

[bimmersbeercan]

Our previous truck was 1500 Sierra 6.2L wit the max trailer option. It pulled our 25FB Flying Cloud just fine. When we traded up to the 27FB Globetrotter, I decided to move up to a diesel again. I still have a BMW X5 diesel that's one of the best vehicles I've ever owned. It had tons of torque and could probably pull the AS just fine but I feel better with a larger wheel base and more mass for the TV.

We were looking for a truck that would stand up for several hundred thousand miles and I'd always been impressed with the Alison transmission. Our 2019 Denali has the 6 speed tranny. We've got 17,000 miles on it now. It's 10" longer than the 1500 and the wife prefers to drive only on the super slabs.

We don't hurry when we're towing and prefer the two lane roads and slower speeds. 16 MPG is not unusual and one time we averaged almost 18mpg across Texas on the back roads, but could have had a tail wind to help. We probably get 13 to 14mpg at 65mph. It drops real fast past that.....

I really like the power when merging from the on ramps. We've only been through real mountains once, but the diesel exhaust braking is fantastic for controlling downhill speeds. Sometimes it works so well that I'll disengage it to let the rig 'run' downhill for speed that doesn't cost.

I agree that the interior/technology is probably the trucks weakest feature. My son in law has a Ford Lariat for comparison.

The truck does sit pretty high so there are come complaints about getting in & out, but overall, it's been a great truck and we have no plans to sell it.

[greenflag]

Duramax/Allison is bulletproof. I have had mine 12 years with 207k on the odometer. Best truck I have ever owned. I previously had a 25' AI. I towed it to Alaska in 2013. We were on the road for five months with our three dogs. We covered 15K miles. We averaged 14.3 MPG for the entire trip. We had access to a SUV from the other couple we traveled with. So the average was nearly all towing. Now that we have a 30', mileage is down about 1 MPG.
I use my truck every day to run my errands. You will get used to the ride. I do park further out in parking lots and avoid parking garages if possible.
It has never left me stranded by the side of the road. Two months ago I jumped in at home, no crank no start. The DIC said "Service Antitheft System". Towed it to the dealer. A module in the computer died. The repair with two new keys cost a little under $800. I have replaced a few items like 3 glow plugs, trailer brake module, power steering hose, fuel gauge sending unit etc.
Service the trans at regular intervals to keep it in top shape.

HAPPY MOTORING.

[Proton]

Moved up from a Ram 1500 sport hemi to GMC 3500 which is just the 2500 with extra spring on rear. Went from a Bayliner Trophy to a Ranger Tug and 16 Bambi to 22 Bambi Sport. Get 19-20 hiway and 15-16 towing the Airstream. My wife likes the size of the truck when traveling in the winter, but the ride is stiff on rough roads. Only minor issues so far. Allison transmissions are the best out there. I hardly use the brakes as the compression brakes suffice. Mine came only with support for electric brakes and did not support electric/surge hydraulic brakes out of the box. Changing the diesel filter is a pain. Recommend you get plier type filter canister removal tool. Also, buy your filters in bulk on line as they will be less than 50% retail. I ran into a problem with water sensor on diesel filter as some filter bases are very tight fit. I make sure a filter and second sensor screw on perfectly if I have to change one on the road. I also carry extra DEF fluid on long trips as there was no way to check what was left.

[moosetags]

I am a somewhat experienced Duramax person. I have owned and towed a 25FB with three of them over the past ten years. Our first one was a 2011 Silverado 3500. We had it for seven years and drove it 130,000 miles, over half of which was towing Lucy. We also had an Outfitter pop-up truck camper at that time which rode in the bed most of the time while towing. Even with the truck camper, we got 12 mpg. We replaced the 2011 with a 2018 Silverado 2500. We drove it 60,000 miles, most of it towing including an Airstream Alaska trip. We got a consistent 13.5 mpg while towing. in March of this year, we traded for a 2020 Silverado 2500. We did this mainly to get the new camera system. Due to this Covid stuff, we have had not gotten a chance to do any towing of Lucy other than to test and set the invisible trailer camera. Therefore, I cannot report any fuel mileage figures.

These trucks are big, but you get used to it after a while. When we go to the stores, we park way out by the street where we can always get a double spot. This is OK with us as we can use the exercise.

Brian

[Jrcat]

We have the same truck. We bought it new in 2009 and then bought our 2009 25-ft International Airstream. It is a perfect combination. The power from the 2500 Diesel makes towing the Airstream a breeze. We live in Oregon and take it over mountain passes all the time, and the truck doesn’t even know the Airstream is back there. They say a diesel truck doesn’t even begin to get “broken in” until 100K miles. We now have 120K on it, and we are seeing that it is indeed true. It is running so well. We are getting about 14 mpg towing. In the beginning, we had a few issues with the mass airflow sensor and finally had to get it replaced. Ever since, no problems. The Airstream also handles very well in windy conditions because of its being so aerodynamic. Hope this helps.

[PJ3718]

[I have had three. An 07, 11 and now a 2015. I would not have anything else. The 11 was a lemon, but drove it 95,000 miles. I have almost that on my 15, with practically no issues. Its going to be my forever truck. They ride as good as a car, and no lack of power. I tow a 34 with a slide, weighing 10,,600 when fully loaded. I average about 11 to 15 mpg towing depending on the terrain. 22-25 highway not towing and that's with almost a ton in the bed. I love the engine brake. Almost never have to touch the brakes, except to stop. I don't like the fact the fuel pump shuts off at 99 mph., but you can get there very quickly. The parking sensors are the best thing since windshield wipers. Can't say enough about the style, ride, handling and the pleasure driving one.

2015 Silverado 2500. Duramax LTZ matching tonneau cover. 20 inch wheels.

2005 34 ft. Classic LTD with slide.


OTE=renderit;2443473]I just bought my "forever truck" because a deal kinda fell in my lap.

How do you like what you have?

Mileage you get with a 25 or above AS?

Break-in etc for these vehicles?

Any limitations I will have?

Particular likes and dislikes?

This thing feels like a TANK. I hope I will not live to regret it.[/QUOTE]

[dscluchfc]

I have a 2002 GMC 2500HD Duramax Allison. Just turned 400,000 miles.
Gets 16.5 mpg mixed city and highway daily driver, and about 12-13 mpg towing my 1984 31 ft Airstream Excella with a GVWR of 8500 lbs at 65-70 mph.

Maintenance is the key to diesels. And fuel filtration.
I use the nicktane.com 1R-0749 Cat filter in line first under the driver side wheel well and then the OEM filter under the hood to double filter my fuel to 2 microns. Change the Cat 1R-0749 every 8000 miles and the OEM every 16,000 miles.
Oil changes every 4000 miles with Rotella and Transmission service every 30,000 miles.

There was major work done at about 282K-288K miles.
Front end got rebuilt with new ball joints, pittman, idler, tie rods, etc. Hib bearings changed out, and new front diff because I spun a nearing and chipped two diff teeth.
Transfer case replaces at 285K because a gear laid over and rubbed a hole in the case.
Allison Transmission replaced at 285K as well with an Allison Certified reman.
Injectors replaced at 288K for the 3rd time and replaced the CP3 pump as well because that caused the failure of the injectors this time. Compression checked at this point and each cylinder was within 10 lbs of new motor.
I also use PJ1 paper filter oil on my air filter and oil and change the air filter each oil change.
Since then 115K miles and nothing but change fluids and drive it.

The Duramax is a beast.....
So much so that I just bought my 2nd Duramax....a 2007 pre DEF, pre DPF with 81,000 miles on it when the 2002 finally gives it up....
Who knows when that might be?
Right now, the driver's seat in the 2002 needs rebuilt with new tan leather....

[guskmg]

I've owned a '01 and a '07 3/4 HD Duramax/Alison. A few minor problems but not much lately. The biggest was a TCM, a glow plug and a fuel rail check valve. One big surprise was a filter then an EGR valve update all caused by bio-diesel. GMC has the market sowed up on diesel 3/4 and one ton truck quality and reliability. They can't be beat.
guskmg

[ckerrick]

Originally Posted by renderit

I just bought my "forever truck" because a deal kinda fell in my lap.

How do you like what you have? I have a 2008 Chev HD2500 4WD crew cab and I like it a lot... it's been a super tow vehicle for my 25' Airstream. Have about 140,000 miles on it now; pretty much trouble free. Only drawback is an occasional low fuel pressure error code that occurs when climbing steep hills in very hot weather in summertime, and the computer then puts the engine into "limp mode", wherein it will only go about 15 mph and can't exceed some low number of RPMs until you come to a stop and clear the code. Worn or failing injectors can cause this, although my injectors show no sign of failure and little wear when tested by a diesel specialty shop. They installed a lift pump for $900 that didn't solve the problem... so I'm still trying to get this figured out.

Mileage you get with a 25 or above AS? Consistently 13-13.5 mpg when towing our 25' Airstream, but that economy is at 65 mph or less. Higher speed drops it down to 12-13 mpg. Open road when not towing it gets about 19-20 mpg, but only 13-15 mpg stop and go driving in the city.

Break-in etc for these vehicles?

Any limitations I will have? Shouldn't have any with a new truck, other than regular/routine and sometimes expensive maintenance (oil changes, fuel filters, transmission service)

Particular likes and dislikes? Particularly like the engine power and torque; makes towing a breeze. Tow Mode engine compression braking works really well and saves a whole lot of wear and tear on brakes.

This thing feels like a TANK. I hope I will not live to regret it.

Although these trucks are big and don't have a great turning radius, they are generally very dependable and relatively comfortable. The Allison transmission shifts smoothly and works very well. My mechanic says this truck's engine and transmission should last 300,000 - 400,000 miles with regular maintenance.

[Hermes]

This is a truck built to haul and tow, and it does an excellent job of it. The previous posts covered the most notable features. On the last 15000 miles towing my 28', I got 13.9 mpg. Not a particularly handy daily driver but it will get you around. Got an extended 6 year warranty since it's my first Duramax. Love towing on hilly mountain roads, takes the stress out of driving. I plan to keep it for a very long time! Good luck.