Jump to content

Recommended Posts

Posted (edited)

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!

Hillcountry.jpg

Edited by camjr
  • Like 1
  • 2 weeks later...
Posted

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

Posted

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.  

Posted
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 

Posted
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. 

 

 

Posted

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.

 

 

  • 2 weeks later...
Posted (edited)

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 by mrfarb
Posted

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. 

Posted

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. 

Posted

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. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,759
    Total Members
    8,960
    Most Online
    DM22
    Newest Member
    DM22
    Joined
  • Who's Online   4 Members, 0 Anonymous, 1,640 Guests (See full list)


  • Latest Articles

  • Posts

    • Did have to make 1 modification because of the WeatherTech rear mud flaps and that was needing 3 longer screws than what came with the install package. 😄
    • Picked up the liners yesterday. Installed passenger side WITHOUT any modifications. All mounting holes lined up perfectly. Rain is interfering today with drivers side. Very Happy! Will add pics when finished
    • As a matter of amusement I’ll leave this conversation with this. Do you beat the government average fuel estimate? Statistics are a guide to me. Not a rule. Someone once said I have to have the last word. If true and possible may be. I’ll blame that on working in a family business.
    • That is a fair point, and I agree that trying to log “everything in the truck” would be the wrong direction.   There are a lot of modules and a lot of traffic. If the product became a full-truck datalogger, the amount of data would get huge very quickly, and most owners would never use it.   I think the first useful version would need to be narrow: - powertrain-side event evidence - selected high-value parameters - communication / voltage / reset events - pre/post event window - short report first, raw log only as backup   One distinction I should make is between active OBD/PID polling and passive bus capture. If you are polling PIDs through OBD, then yes: the more parameters you request, the lower the effective sample rate becomes, and you are adding diagnostic traffic to a vehicle that is already busy running itself. With passive CAN capture, the recorder is not asking all the modules for data. It is listening to traffic that is already on the bus. So it does not consume vehicle bus bandwidth in the same way that a scan tool polling hundreds of PIDs would. But your point still applies in a different way.   Even if passive capture does not add bus traffic, the recorder still has limits: - processing rate - storage rate - timestamp accuracy - decoder workload - event filtering - report size - user attention span   So the answer cannot be “log everything and let the user figure it out.” The product would need to store enough raw evidence to be useful, but only decode, graph, and present the important parts around the event.   A practical report should probably show: - what triggered the capture - how much pre/post data was preserved - which selected parameters changed - how those values compared to baseline - whether the same pattern happened before - whether any voltage, reset, bus-off, lost-message, or communication fault occurred - selected graphs around the event - raw data only as supporting evidence   So I agree with you. More data is not automatically better. The real product is the reduction from raw data into a useful event report.
    • That makes sense, and I agree with most of that.   I think the product would need both: 1. a default powertrain template, so it is useful out of the box; 2. user-selected priority parameters, so the owner or shop can choose what they want to see first.   Different users are going to care about different things. One owner may care about oil pressure and voltage. Another may care about misfire trend, AFM/DFM behavior, or U-codes. A shop may want communication events and repeatability first. Your baseline point is probably the most important one. Raw data is not very useful unless the report can show what normal looked like for that vehicle under similar conditions.   The way I would think about it is: - start with a basic known-good baseline - learn normal behavior for that specific vehicle over time - allow the event to be overlaid against baseline - show whether the event was a one-time spike or a repeatable pattern - provide a simple severity level, but with clear limits on what that severity means   For example, early severity could be something like: - Info: event captured, no obvious abnormal pattern - Watch: value moved outside baseline, but not repeated - Warning: repeatable abnormal pattern under similar conditions - Critical: communication loss, voltage drop, bus-off, reset, or severe repeated event   I would not want the first version to say “replace this part.” That would be overclaiming unless there is repair-confirmed data behind it. It would be more honest to say “this pattern deserves inspection.”   On the OBD port question, I think OBD absolutely has a role. OBD is probably the right place for: - DTCs - freeze frame - VIN - calibration information - normal scan-tool parameters - Mode 6 / enhanced diagnostic data if available The reason I am still looking at an ECM-side recorder is that the failure may happen before anyone connects a scan tool. If the owner plugs in a scanner after the event, the pre-event evidence may already be gone unless the ECU happened to save it. So I do not see this as “OBD versus ECM-side.” I see it more like: - ECM-side recorder: always armed, rolling buffer, event evidence - OBD/DLC companion: DTCs, freeze frame, VIN, calibration, normal scan data - phone/cloud: status, notes, upload, report generation, notifications   I agree that phone connection and push notifications would be useful. I just would not want the phone or cloud connection to be required for capture. The recorder should save the event locally even if the phone is not connected. The phone should help with event marking, download, notes, upload, alerts, and report viewing.   For a default GM V8 event report, would this list make sense? - RPM - calculated load / MAP - throttle position - vehicle speed - gear / torque converter state if available - coolant temperature - oil pressure - oil temperature if available - battery voltage - commanded AFM/DFM state if available - actual AFM/DFM state if available - misfire counters / roughness by cylinder if available - fuel trims - relevant U-codes / communication events - bus-off / lost periodic message / module reset / voltage drop events Which of those would you remove, and what would you add?
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...