Calling 2020+ GM 25/3500 6.6 Gas Owners

Looking for some more long term feedback on the guys who went to the HD side of things the last few years. Out of all the GMC/Chevy HD guys posting to the prior threads how are the trucks holding up? The closer I get to buying a truck the more I’m thinking of departing from Toyota and just stepping up to a Chevy 3500 gas to be done with it and never have to fret about towing or payload numbers as my family continues to grow. Thanks all.

 

I do not own one of the trucks you're talking about but have a friend that does. . And if I were to jump ship with toyota (I'm not) that's exactly what I'd get. . He's got a 6.6 gasser gmc. . No d.o.d. and I believe a six speed that's tried and true (if that means anything with a g.m. tranny). . Plenty of power, decent mileage and plenty of payload. . He loves his for what it's worth. . And he actually got it for less than a comparable 1500

 

The new gassers get the 10 speed, I believe.

The AT4X HD looks cool. It seems like a Tremor Super Duty, except I would trust it a lot more. I probably will not pay what they're gonna ask, out of principle.

My kids keep getting bigger. And the family is wanting bigger toys. I would hate to trade the Tundra in, but I may be forced into it.

 

I moved to an F350 gasser from the Tundra, had some problems with the Ford and found a Sierra HD 2500 Duramax. Different engine than you are looking at, but so far it's been incredibly reliable. Tech is great. Truck looks good, is comfortable, has power in droves.

Miss both of my Tundras but wouldn't go back unless I could have a second truck.

 

My 6.6 has been fantastic for the 30,000 miles I’ve had it. I know others have far more miles than mine, but it’s been a great truck for me. Only “issue” is the squeaking brakes you can hear one state away, but it’ll be resolved whenever I eventually replace the brake pads.

 

2021 GMC 3500 gasser with 6spd. I will roll over 70k miles in the next week or so. Bought it new from the dealer. Truck does exactly what I need to and I’ve pulled max loads a lot. Maybe a few loads that were over. Truck is solid. A couple of annoyances with build quality. A few rattles here and squeaks there, but they were all fixed for less than $200.

Only real concern I’ve had was the hard shift in the transmission. Dealer replaced the transmission valve body no questions asked. Haven’t had the consistent issue since.

I’ll be honest the new 10spd has caught my attention. I’ve seen real world tests that prove it’s better performance and the trucks get around 1mpg better. The thing that kills me is the price. I bought my truck for $47k OTD. If I was buying now I would get the Chevy 3500 with the 2LT trim or add a few items from that list. Would put the truck in the low $60s.

Pics because why not. 2nd photo is a pallet on cement bags. 3400lbs. Still had 600lbs left

 

Overall I’m happy with my 2021 GMC AT4 2500 gasser, 54k miles so far. My biggest complaint is the oil usage while towing through the hills. Last month I did 1200 miles round trip from Seattle to East Glacier MT, burned a couple quarts. Mostly I commute with the truck, no noticeable drop in oil levels when not doing the long towing trips.
TBH, if I could go back I would pay the extra $10k and get the diesel.

 

Price is my issue as well. My truck was $48.5k, and the exact same spec truck with 10 speed is $55k at minimum

 

So far I love my 2024 AT4 3500 gasser. I had a 2010 DC Tundra and loved it—it never gave me any trouble and I was honestly sad to see it go. However, I was in the same boat as you regarding payload with a family of four, our travel trailer, and a bed full of gear. When it was time for a new truck I knew I'd want a crew cab with the kids getting older and would have gone with a new Tundra had I stayed with a half ton, but when the 2022+ came out and I saw essentially the same payload numbers (and I'm still not a fan of the looks), I went searching for an HD gasser. I drove the 7.3L "Godzilla" and the GM offerings and loved how the GMs rode compared to the Ford, plus the 2024 refresh with the redesigned interior and 10-speed transmission with the gasser led me to order the GMC. The Ford dealer said I could just order the F350 I wanted and that they would just get to keep the extra allocation if I ended up not wanting it. I ordered both the AT4 and F350 in March—I picked up my AT4 in mid June and the Ford still doesn't have a target production date... Even if they showed up at the same time I still would have gone with the GMC.

Anyway, I've only had it for about three months and have about 3500 miles on it, but I haven't had any major issues. There were a couple minor things that popped up early that the dealer fixed or I took care of myself. The 10-speed has been fantastic for towing and always seems to stay in the power band without shifting all over the place. It's a totally different experience than a half-ton, but for the amount of money a new Tundra costs I'd do it again.

 

Just curious, have you talked to the dealer regarding the oil consumption? From what I've heard GM says a "normal" amount of consumption is 1qt per 100 gallons of fuel. If you're getting ~9mpg towing, that would be 1qt per ~900 miles. Burning a couple quarts over 1200 miles seems kind of excessive (even GM's "normal" amount seems excessive to me, but whatever).

 

Thanks for the feedback everyone! This forum is awesome and I appreciate you all taking the time to document your experiences so far. Navigating and getting real world feedback in the GM forums regarding these trucks is difficult so it’s great to have a place where prior Tundra owners can compare build quality, capability, and reliability with increasing mileage and age.

From the limited info I found most of the complaints were related to oil consumption mostly with towing which echos @A-A-Ron. Good to know that unloaded it is not an issue currently.

With the rising cost of vehicles in general it seems that for the truck category the HD gasser is the best bet for cost, capability, and initial reliability.

My use case will be a family of 5 living in Alaska and utilizing the truck to explore and also work as trucks were intended. We like to camp and I’ll likely get a slide in camper which basically pushes me to an HD regardless. Slide in will allow me to use it hunting in the fall and still tow a trailer with 4 wheelers/skiff if needed. Will be towing and hauling firewood a few times a year. I have also developed an older land cruiser addiction and would like to flat tow project/parts rigs.

I am not a tech guy and don’t really care about cutting edge features/electronics. I plan to keep the truck for 15+ years so my main focus is reliability and longevity. I’ll likely end up in a work truck spec crew cab 4wd with a long bed, maybe an LT or other mid grade trim if the price is right.

Hopefully this thread can serve as a check in place for people with this generation truck as issues pop up or to provide further data points with increasing miles and uses if this gen is as robust as it seems.

Thanks again to everyone who has contributed so far.

 

I totally agree, the GM forums are not great, especially compared to this forum. I feel like I get better info from the few people here with GM trucks than everyone else on any GM forum!

The LT trim is still great and pretty well-equipped in my opinion. That's what I originally ordered (LT with Z71 Sport package), but my wife liked the AT4 better and said I might as well get what I really wanted if I was spending the money, so I didn't argue!

 

After walking around the Toyota lot and seeing what they’re asking for these new tundras, one would need to have a brain aneurysm IMO to buy one of them over a new 3/4 ton almost regardless of use case. Especially since the reliability seems to have fallen off from the prior gens. If I needed a new truck tomorrow I’d make the very same choice on the GM 6.6 gas. They seem to be trouble free on the pages I follow aside from questionable oil consumption with some of them, and the squeaky brakes.

 

One thing to note on the work trucks I believe the center jump seat doesn't have storage. I would opt for the SLE trim from GMC (which I have) or the LT. And once you buy, let @ColoradoTJ know and he can add you to our group message. Our group message is 100x better than any GM forum.

 

Appreciate it. Might be a little while yet but I will definitely reach out to get in that group message once I’ve purchased one. Thanks again.

 

I've said it before and I'll say it again - we need Tundras.com community and quality with GM content..

Sign me up.

 

I talked to the dealer I use for maintenance about the oil consumption a while back. They put me on a program that I stop by every 1,000 miles so they can check it. If I don’t go on a major towing trip then when they check it everything is fine. When I do go on a major trip I have to add oil because the warning light comes on. Since I only do two big trips a year the whole thing was a joke. I arranged with them to stop going in but the oil consumption is officially documented. I have the extended 100k warranty with the lifetime powertrain, if there is a major problem with the engine before I sell it at least it will be covered.

 

What were these issues?

 

First was my tailgate randomly opened on its own twice. I thought I might have hit the release the first time, but it happened again so I looked it up and it apparently is very common. The dealer found a shorted switch, replaced it, and it hasn't happened since.

Next, and this is a frustrating one, the first time we towed I kept getting "trailer brakes disconnected" notices and would lose my trailer brakes. I pulled over and messed with things for about 3 hours until it finally stopped doing it, coincidentally after the sun started going down. The dealer said there were no codes or issues they could find and suggested it was an issue with the trailer. My trailer is only a year old and I had just towed it a few weeks before with my Tundra with no issues. Anyway, a couple weeks later there is a TSB that comes out saying trailers with solar or generators can backfeed voltage into the brake controller if the solar charges the trailer battery higher than the truck battery, which shuts down the brake controller. I wired in a solar disconnect on my trailer to shut off the solar when I'm towing and haven't had an issue since. I guess there is an official fix for it now but I haven't been into the dealer.

Lastly, I had a whistling noise at a certain RPM due to a loose bolt on an exhaust flange. The dealer "couldn't duplicate" it, so I found it myself and fixed it.

 

We will only buy 2011-2019 3500s with the old reliable 6.0 gasser for work, personally. Never had a single issue with one. Not with the two 5.3 engines we have either to be honest. I just prefer the Tundra for our personal vehicle.

 

Had issue with oil consumption, was about one quart every 1000km, one truck had funny shifting that persisted, I kinda like them cause the way it looks.

3/4 tons are alway a compromise.

 

I thought they initially came without storage then it was added at some point (can't remember exactly which year).

 

I doubt I'd ever buy a 2500. A 3500 is usually only a few thousand dollars more for quite a bit more capability.

 

That’s good. That original decision to take out the storage was so stupid.

 

For my 2022 SRW L5P crew cab, standard bed, a 3500 only offers about 1500lb more bumper pull capacity and around 2000lb more gooseneck capacity. You don't see a huge gain in capability until you go to a DRW.

That said I fully agree with your logic. I went from an F350 to a 2500. I was originally looking at a 3500 but hesitated and it was gone the next day. Found a 2500 with an almost identical build sheet otherwise and jumped on in.

18500 bumper pull is more than I need by about 80% as it stands. No need to haul a 5th wheel yet, but I don't imagine hitting 20k lbs there either.