3.0L Duramax - who owns or has driven one

[camjr]

I just took my 2021 X31 Elevation 3.0l Duramax on it's first road trip of significance - a 900 mile round trip down to the Texas Hill Country from north of DFW.  We did quite a bit of driving on the twisty roads through the Balcones Escarpment, in addition to winery and brewery tours, shopping, and just getting away.  Mileage for the entire trip, including the city and small town driving, starting and stopping, lots of rain, etc. was 24.1 mpg on the computer, and 24.3 by hand.  Best mileage over a rolling 50 mile average was 28.3 on the DIC (that figure was hit twice).  Cruise control used as much as possible at 2-4 mph over posted speed limits.  Plenty of passing power on two lane highways.  I'll take that!

 

Now, this thing needs a serious wash!

Edited July 6, 2021 by camjr

[Dunn]

i have same truck color in same trim, different motor but i love the cayenne red......everytime i see it i still love this color......one time early on i walked out of a store and looked at it (forgetting it was mine for split second) and thought jeez thats a bad ass looking truck, oh wait!, ****** thats my truck. lol

[loopbacksean]

Just managed a 50mpg average of 35.5mpg on my silverado z71 cc w/ 6.5ft bed cruising down I-75 in MI. That's absolutely insane.

[Elstro17]

The truck is a great truck, but we are all having issues with the starter engaging and truck not firing.  From reading posts, many trucks have been in the shop for weeks and they haven’t figured it out yet.  Very frustrating.  

[Elstro17]

Amazing truck, love it.  Hope they fix the starting issue.

[Michael Ridley]

On 9/2/2019 at 12:38 AM, redwngr said:

There are some starting to show up at dealers near here.

 

Reviews would be appreciated.

Just got my 2021 Suburban Duramax delivered Saturday and with 26 miles it is already in the shop. Has 10 codes and they claim it is over fueling. Hopefully this isn't a foresight of future. Instantly regret buying 

[redwngr]

2 hours ago, Michael Ridley said:

Just got my 2021 Suburban Duramax delivered Saturday and with 26 miles it is already in the shop. Has 10 codes and they claim it is over fueling. Hopefully this isn't a foresight of future. Instantly regret buying 

Post quoted was about 2 years ago.

I ordered and bought a 3.0 Sierra last fall.  (9 -10 months ago)

 

Just turned over 10,000 miles.

They had a few trucks that had issues with the coolant distribution valve. Mine was one. Popped a code when it was idling while we were doing the onstar and xm delivery thing.

 

 

Wasn't happy that day, but it's been flawless since the replacement. (and it has never done the crank/no start thing)

I'm really really happy with it. 

 

 

[6sigma]

I have 10k miles on my 2020 Sierra AT4 CarbonPro I got in early 2020. It's been a great truck, just a few minor concerns/questions.

 

1. I've had 2 CELs, both some code that has something to do with the brake system. Both went away almost immediately, so never even got a chance to have the dealer look at it. Have not had one recently and I wonder if some software update along the way may have addressed this.

 

2. I have the adaptive cruise and it works well. My complaint is when traffic clears in front of you, the truck drops the hammer and downshifts to about 4k rpm. The minimax has enough torque it does not need to downshift and rev to the moon. I think the trans programming could be better adapted to suit the dmax. 

 

3. I've noticed if it idles for 5 or so minutes it will sometimes move into a high idle mode, even in high air temp and when the engine is warm. Similar to when it is in regen mode but I don't think it is doing a regen. I assume it does this to keep the cat/DPF hot, but what seems weird is that it seems to stay in this high idle mode even after driving around some. I don't think it is a problem, just seems odd and I don't understand what it is doing. Actual regens are only slightly noticeable with a higher idle and a change in exhaust tone. I've had a couple regens start immediately after long highway drives, which is bad timing cause I've been in stop and go slow speed traffic and it's trying to regen. Again, not a problem, but would have been more efficient if regen'd at highway speed.  

 

My wish list is short. 

 

1. Display the current gear somewhere

2. I'd like a boost gauge option

3. I'd like a light or indicator of when it is in active regen mode

4. Change the trans programming to hold a gear with more throttle (don't downshift as readily) since this thing makes peak torque at like 1600 rpm.

5. Tune the exhaust brake to be more effective. I don't really know if it is doing something or not. Maybe I've never had it in a scenario where it has really needed it. If it really is there, make it more effective. 

 

Overall love the truck and 10/10 would buy again. In fact, if the 2022/3 refresh looks good I may upgrade and get the same truck again.

 

 

[mrfarb]

Bought mine in Dec with Employee pricing, Z71 4x4 RST Duramax. Was nervous about the Duramax, but 2nd year model seems to be safe. So far I have put about 26,000 miles on it. My lifetime average is 23 MPG, but I do a lot of city driving. Best 50 mile average is an incredible 36.7 MPG coming from Louisiana to Houston with cruise set to 65. I was stunned! While I do city driving a lot in Houston, I do some highway driving too. This is the smoothest, best running truck I've owned. I don't tow anything, or even drive off road much, but when I need 4x4, I need it.

 

I'm a high mileage guy, the 150,000 mile oil pump belt inspection/service is odd to me, but I once put 400,000 miles on a 2005 I5 Colorado so I know how to make them last.

 

But, i'm with 6sigma, when the 22/23 refresh comes I may just trade it in on a new one!

Edited August 12, 2021 by mrfarb

[mansonbill01]

I have a 2020 Silverado LT woth the 3.0 L Duramax and 10 spd trans. We completed an 8K trip cross country over 7 weeks and had no issues. I averaged 14.5 MPG overall which I thought was great. I have 38K miles on the truck and just had the trans serviced because GM recommends if you tow a lot or severe use it should be serviced at 37,500. 

[Pawg]

only 700miles of smiles... best has been 30mpg doing 80 on NY turnpike with a lttle traffic.  Things pulls, it's quiet, love it so far.  Only thing I dont like is the 0-20 oil.  Thats baby oil.  I se no reason why 5-30 ESP wouldnt be safe for the SCR/ DPF and decrease mileage.  The oil pump will be fine, everyone is all worked up about the belt driven pump.   If you have to pull the tranny to replace the belt, I can see that as expensive if you take it to a shop.  It is something you can do on a lift if you have access to one.  Plus I am sure the belt would last a lot longer than 150k, I have seen timing belts last for 200k plus on gassers turning 3000 rpm all day.  My 3.0 does around 1500 at 80mph, maybe less.  The pump is variable and nobody really knows how long it will last. 

[mark1968]

We just got back from a round trip from MN to VA to IL to MN over the last few day to drop kids off at 2 different colleges. Our truck (2020 gmc 1500 denali 3.0) did amazing the entire trip.

Recap: 2550 miles with avg of 28.4 over entire trip and only 2 blips down on full def tank- we didnt tow anything.  In fact a full tank looks like it could almost do 800 miles total on the open road. Truck now has 18k basically trouble free miles on it now. We are thrilled- very comfy and cruises the open road perfectly.