3.0L Duramax - who owns or has driven one

ullose272 · June 24, 2020

2020 GMC Elevation CC Standard box x31 (3.23 gears). 2500 miles now. Installed the autostopper first thing. best mod to date.
22 mpg around town taking kids to school/grocery run. 28mpg at 80mph on freeway work commutte (80 miles round trip). Best ever over 50 miles is 30.8. Both my wife and I love driving this truck, its quieter and funner to drive than our 2019 traverse (autostop, shitty 8 speed, but the wife gets what she wants...)

Towing: I have a 32 foot RV, 11 feet tall, with 6400 weight/600 tongue. GVWR 8000. (imagine 2800BH for curious) By the time we load up with all the camping gear, dog, 2 kids, bikes, etc were right at or over GVWR for trailer and max or over on towing weight, I do run a distribution hitch. But my wife takes the literal mobile home seriously and we have all sorts of useless ****** in the trailer because she might need it...

I had to put airbags on the truck after the first camping run. 3.75" of squat without them (6 pedal bikes in pickup bed). With the airbags the truck tows like a freaking dream and 0 squat. (45 PSI). Ive even found that 10psi in the bags seems to run smoother than with 0psi in them and no weight in the bed.

I live in a state with 80mph freeways and 10k foot passes and steep grades. Ive been averaging 12 mpg pulling the trailer. My 6.6 LBZ duramax never got that pulling the same RV. Ever. Wasnt even close to that. My 2014 Ram 5.7 hemi was lucky to see 8mpg.
She typically runs in 9th at 1800 rpms but always down shifts for an sort of an incline (like an overpass) at 80mph. I've pushed the truck towing to see what it can do, I wanna know its limits. She sucks the DEF fluid when towing but she doesnt back down from any grades or temps. Last weekend i pulled a long 8% grade on a state highway at 90 degrees temp (roughly 5500 ft above sea level). Tranny temps stuck at 205 and engine just above 210. She wouldnt hold 75, but tranny ran smooth and it ran over the top at 65 mph. The truck ride and performance with a trailer on is top notch and smooth.

I did find that the sweet spot for towing my RV was 70mph. It will run in 10th at 1500rpm all day with hardly any shifting and i can eek out 15-17+ mpg

Overall this is the truck I have waited years to own. Inline 6 small diesel with outstanding fuel mileage that can pull everything I really need it to. Its so quiet and smooth that my family loves riding in it, its spacious and roomy (my dog fits in the back seat with the kids, unlike my lbz or hemi crew cabs).

Things I dont like:

autostart/stop. Put the autostopper on (30 minutes to pull dash apart) and took care of that nonsense

no part numbers yet to install the bed 120v outlet of 400w. I put ebikes in the bed as well as snowmobile gear and running a boot/glove dryer on the way to my destinations is a must. Was told this came on my truck, wasnt there when i picked it up, dealer has been less than helpful in making it right.

Interior was not as nice as the ram, but the 3.0 drive and ride was much better IMO, hence I ended up with the GMC.

no wireless apple car play

cupholders are for childrens sippy cups. nalgene and hydroflask are way too big. Make some big cup holders GM. You can always buy inserts to make them smaller.

silver lug nuts on black wheels, chrome elevation badges need to go. The Ram night package is about as sexy as it gets for style. GMC needs to get it together.

24 gallon fuel tank. There is room under there for 32 gallon. give us what we want

DEF consumption while towing. She is thirsty, 3-4 hour drive towing your going to fill up with DEF somewhere along the way home.

What gears?

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Benzo1 · June 24, 2020

29 minutes ago, ullose272 said:

Got any pics? How much lift?

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No Lift - just removed the rear 2" block to level the truck and installed Bilstein 5100 (rear only).

Phatty · June 24, 2020

1 hour ago, Benzo1 said:

Great Review! Couple questions as I also have a 3.0L Duramax and tow a trailer of similar weight...

What Airbags did you go with?

When running 10psi how much different is the ride compared to without the airbags?

And BTW - love the Imagine Trailers. Looking to sell our current ToyHauler and get a new Imagine as well...

I went with the firestone. Ive been an airlift guy for years, local shop gave me a deal on the firestones. So far they are just as good as the airlifts on my other trucks.
The ride with 10psi does not seem to be as bouncy. I have the rancho shocks on the x31 package and they tend to bounce a little unloaded. 10PSI seemed to give me a more planted feel. If that makes sense.

Imagine trailers are so nice. Fit and finish wise we love it. The heater leaves a lot to be desired, their only weak spot IMO. Wish they made a 26 foot BH model, I think we may downsize to the 2400BH just to have something a little easier to fit in the driveway and backwoods.

Phatty · June 24, 2020

1 hour ago, ullose272 said:

What gears?

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3.23 I would have loved the 3.73 but by the time I was buying a truck I couldn't find the configuration I wanted (front bench, standard box, CC, elevation) with the offroad diesel package and the 3.73 gears. Something has to give and it was the gears.

PBrown1 · June 25, 2020

I just bought the 2020 Silverado 1500 3L Duramax. I have about 1200 miles on it. So far I love it. It's very quick, quiet and the tranny is super smooth. I get about 22mpg city and I have gotten 29mpg hwy. I have a 21' Hurricane deck boat on a tandem trailer and it easily pulls it. There I get 12-14mpg. Yes it's new and I hope there aren't any design flaws. TBD. So far, great truck!

PA Farmboy · June 27, 2020

My two cents...

Well, in February, we traded our 2016 Chevy Colorado with a Duramax in for a 6.2 L 2020 Silverado. Yes, we wanted a bigger truck, but the main reason we traded our Colorado in was we hated the hassles that came with the Duramax engine - DEF fluid and numerous sensor problems. I had discussions with my dealer's mechanic who said everything changed with diesels when the EPA started mandating DEF fluid and having additional sensors for diesel vehicles. They just caused more heartache than they were worth. Thank you Barrack. The truck was almost paid off and really babied. It only had 21K miles on it at trade in as we used it for in and around town driving and working on our farm. Gas milage and power were great; however, dealing with DEF fluid sucked and taking it to the dealer every other week because of a bad sensor really pissed us off as the truck was honestly unreliable. BTW, the big Duramax in the Silverados have even more diesel sensors than the 2.8 that was in our Colorado. We decided to go with something that just burned gas. Granted our new Silverado is the USS Enterprise to the Colorado's space shuttle, but no more aggravation in dealing with the Duramax.

ullose272 · June 27, 2020

My two cents...

Well, in February, we traded our 2016 Chevy Colorado with a Duramax in for a 6.2 L 2020 Silverado. Yes, we wanted a bigger truck, but the main reason we traded our Colorado in was we hated the hassles that came with the Duramax engine - DEF fluid and numerous sensor problems. I had discussions with my dealer's mechanic who said everything changed with diesels when the EPA started mandating DEF fluid and having additional sensors for diesel vehicles. They just caused more heartache than they were worth. Thank you Barrack. The truck was almost paid off and really babied. It only had 21K miles on it at trade in as we used it for in and around town driving and working on our farm. Gas milage and power were great; however, dealing with DEF fluid sucked and taking it to the dealer every other week because of a bad sensor really pissed us off as the truck was honestly unreliable. BTW, the big Duramax in the Silverados have even more diesel sensors than the 2.8 that was in our Colorado. We decided to go with something that just burned gas. Granted our new Silverado is the USS Enterprise to the Colorado's space shuttle, but no more aggravation in dealing with the Duramax.

I really dont see the issue with DEF, in 3200 miles ive filled it once. 3.5 gallons, pulled up to a pump and filled it up. Just as easy as fuel.

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PA Farmboy · June 27, 2020

ullose272

I agree DEF got easier since they started putting it at stations, but we still didn't have it at the stations in our area. The GM gauge on the instrument panel is terrible, coupled with he numerous sensor issues made it problematic for us. When you have a sensor go bad, it would pop up on your dash display saying maintenance require, covering up the entire instrument panel. When it takes two weeks to get your truck in for an appointment, that sucks. You can drive it for a while in that state, but each time you get in the truck to go somewhere you get this ominous mileage countdown and from what we were told at our dealer, you don't want to run the truck to the minimum because you will introduce new problems.

newdude · June 27, 2020

9 hours ago, PA Farmboy said:

It only had 21K miles on it at trade in as we used it for in and around town driving and working on our farm.

This. This is why. 5200 miles a year of city driving and farm idling. We have farmers in the area that own newer DEF equipped diesels. The way they use them seems to have a correlation with emissions system component failures. The sensors in the exhaust system can carbon up faster over time when they just sit and idle or putt around town. The ones we see in with 20k a year mileage that get driven and worked are mostly trouble free.

Edited June 27, 2020 by newdude

Phatty · June 29, 2020

On 6/27/2020 at 6:50 AM, newdude said:

This. This is why. 5200 miles a year of city driving and farm idling. We have farmers in the area that own newer DEF equipped diesels. The way they use them seems to have a correlation with emissions system component failures. The sensors in the exhaust system can carbon up faster over time when they just sit and idle or putt around town. The ones we see in with 20k a year mileage that get driven and worked are mostly trouble free.

Both my buddies with the 2.8 Dmax had all sorts of sensor failings on them, both traded out, one to the v6 colorado and one to a raptor. Both of them drove long distances for work and for weekend activities including 15+ highway miles)
think its the 2.8 design/sensor product problem and not the way people are driving them.

Kchampagne · July 3, 2020

Does anyone know the weight of the 3.0 vs the 5.3 or 6.2? Thanks!

Pyroman_28 · July 4, 2020

On 6/24/2020 at 10:01 AM, Benzo1 said:

Thanks for the feedback! I recently installed new 34" tires and have yet to tow my travel trailer. We'll see how she performs before making a decision.

I've got 35" tires and a 6" lift with 3.23 gears and I'm getting around 13-15mpg at 65mph. My toy hauler weighs around 6000lbs loaded with about 700 on the hitch. I was really debating getting airbags as well but after towing it a couple times I'm more than happy with how it tows with just the weight distributing hitch.

kenny_r · July 4, 2020

I've got 35" tires and a 6" lift with 3.23 gears and I'm getting around 13-15mpg at 65mph. My toy hauler weighs around 6000lbs loaded with about 700 on the hitch. I was really debating getting airbags as well but after towing it a couple times I'm more than happy with how it tows with just the weight distributing hitch.

Nice, do you feel it ever tries to find the right gear going down the road with the trailer? Mileage seems really good as well.

redwngr · July 4, 2020

On 7/3/2020 at 12:38 AM, Kchampagne said:

Does anyone know the weight of the 3.0 vs the 5.3 or 6.2? Thanks!

3.0 is a couple 100 lbs heavier, based on payload ratings.

There is a weight calculator if you're wanting to compare weights for specific models and trim levels.

https://www.gmfleetorderguide.com/NASApp/domestic/weightcalc.jsp?vehicleid=21796&regionid=1&step=1

Edited July 4, 2020 by redwngr

LowCountryDenali · July 7, 2020

New to this forum. Took this one for a test drive the other day. Dark Sky Metallic loaded Sierra 1500 SLT with 3.0 Duramax. I've owned diesels since 2014, Mbenz GL 350 and current BMW X5 35d. The Duramax is much more refined than either. Impressive acceleration and quite torquey. I'm not a hauler/tower. Some of the lease numbers I've look at are quite favorable and I'm very close to pulling the trigger. Based on what I'm seeing the residual on a 36 mo/12k lease must be 60%+. Anybody out there who can confirm?

Edited July 7, 2020 by LowCountrySLT
grammar