I'm averaging close to 17 with my 6.2. It's really good if you keep it in the 40/45 mph range (like 23/24). But I noticed even on the highway doing 65/70 I'm lucky to get 21 on average. Of course in PA where I'm at we have hills, which doesn't help. The commute to work is more downhill and I do better than coming home. She is a thirsty girl... but when you need the power there's nothing like it. I'm coming from a 2012 5.3, and while it was nice, there's nothing like the 6.2!
Fuel economy with the 6.2
- Thread starter ArcticHC
- Start date
I had to add this here. Noticed it this morning.
Like seeing a unicorn.....
I just filled the tank and reset the trip computer. Was driving downhill the full 1.5 miles.
It corrected quickly after that.....
Teegunn
Well-known member
A couple months ago, I had a check engine light come on in my 6.2 2023 AT4X. I hoped the code would clear itself, but it didn't. I took it to my local dealer, the service tech brought out a code reader and about 15 codes came up. I will have to dig up the paperwork for the main codes, but the service manager looked at them and said "either your engine is going out or your transmission". I was like, what the hell?
They said they had a two week wait to even get an appointment, but that likely the truck could be in their shop at least 3 months, maybe 6 months (parts issues mainly). This truck is my only vehicle, and I use it daily for work and also my daily driver. The truck had about 20K miles on it when the check engine light came on.
I left the dealership baffled and confused. I still drove and used the truck, but it was not running right - it was surging on idle and either not shifting as smoothly, or the engine was surging some while driving. The check engine light finally went off on it's own about a week after taking it to the dealer. I had been in the process of looking for an older 2008 to 2012 GM truck to use if my 23 AT4X actually had to be down for 3 to 6 months.
After the check engine light went off, things were a little better, but still not right. Still some surging at idle, some not quite right shifting, and while using cruise control, the truck will slow down 3 to 4 mph before finally slowly trying to get back up to the speed I set the cruise at. It never lagged on cruise like that before. The biggest thing though, is that the MPG is WAY down from what it was before the check engine light - like 3 to 4 MPG lower. And while towing it literally gets about half the MPG it did before while towing my job trailer. TBH I was even driving it a little easier anyway since I didn't (and still don't) know if the engine, transmission, or what is wrong with it. But it sucks to have to fill up at 250 miles instead of 350 miles - I lost about 100 miles per tank of range.
I had to go work out of state, and gambled and drove my truck 1000 miles to work. While I was in Nebraska working (I live in Montana), I took my truck to the dealership in NE where I bought it 9 months ago. I told them about the issues, showed them the print out from the other dealership of the codes that came up when the check engine light was on, told them what the other dealership said it "might be".
While my truck was at the Nebraska dealership, my father in law passed away back in Montana unexpectedly. So I took my parents car and drove back to Montana for the funeral, burial the next day, and obviously to support my wife. While I was back in Montana for the funeral stuff, the Nebraska dealership called me and said they were able to read all of the codes that popped up from before, but that GM says it is a "known issue" with somekind of what they think is software/update issue. GM is supposed to be "working on a solution", which sounds fishy to me.
I drove my parents car back to Nebraska after 3 days in Montana for the funeral stuff, as I had to finish up the house I am building for my parents in NE. I got my truck from the dealership. Nothing changed - still slight surging, not quite right shifting it seems, and still crappy fuel mileage. I have now driven it about 4000 miles since the check engine light first came on in late September. I am not sure what to do, but I think I will take it back to the dealership here in Montana again. I am just not OK with a 75K truck suddenly having these issues, and losing about 20% MPG if not more, 9 months and 20K miles into ownership. It still works for me, pulls my job trailer, etc. But I wonder if I am driving a ticking time bomb either with the engine or transmission.
If anyone is wondering, I am vigilant keeping up on oil changes, maintenance, etc. I don't drive my truck very hard, but also don't baby it. I do pull an enclosed job trailer that weighs 5 to 6K lbs when full inside (it is usually very full inside with tools, materials, etc). But I don't think that is a rational reason to think that this truck has been used too hard, etc.
IDK what to do. I will likely be past 36 K miles in about 4 months. Drivetrain and engine SHOULD be covered up to 60K, and I also bought an extended warranty that is bumper to bumper up to 60K miles. I just don't want to chance having a truck that goes out of warranty without having these issues fixed by GM as they should be.
They said they had a two week wait to even get an appointment, but that likely the truck could be in their shop at least 3 months, maybe 6 months (parts issues mainly). This truck is my only vehicle, and I use it daily for work and also my daily driver. The truck had about 20K miles on it when the check engine light came on.
I left the dealership baffled and confused. I still drove and used the truck, but it was not running right - it was surging on idle and either not shifting as smoothly, or the engine was surging some while driving. The check engine light finally went off on it's own about a week after taking it to the dealer. I had been in the process of looking for an older 2008 to 2012 GM truck to use if my 23 AT4X actually had to be down for 3 to 6 months.
After the check engine light went off, things were a little better, but still not right. Still some surging at idle, some not quite right shifting, and while using cruise control, the truck will slow down 3 to 4 mph before finally slowly trying to get back up to the speed I set the cruise at. It never lagged on cruise like that before. The biggest thing though, is that the MPG is WAY down from what it was before the check engine light - like 3 to 4 MPG lower. And while towing it literally gets about half the MPG it did before while towing my job trailer. TBH I was even driving it a little easier anyway since I didn't (and still don't) know if the engine, transmission, or what is wrong with it. But it sucks to have to fill up at 250 miles instead of 350 miles - I lost about 100 miles per tank of range.
I had to go work out of state, and gambled and drove my truck 1000 miles to work. While I was in Nebraska working (I live in Montana), I took my truck to the dealership in NE where I bought it 9 months ago. I told them about the issues, showed them the print out from the other dealership of the codes that came up when the check engine light was on, told them what the other dealership said it "might be".
While my truck was at the Nebraska dealership, my father in law passed away back in Montana unexpectedly. So I took my parents car and drove back to Montana for the funeral, burial the next day, and obviously to support my wife. While I was back in Montana for the funeral stuff, the Nebraska dealership called me and said they were able to read all of the codes that popped up from before, but that GM says it is a "known issue" with somekind of what they think is software/update issue. GM is supposed to be "working on a solution", which sounds fishy to me.
I drove my parents car back to Nebraska after 3 days in Montana for the funeral stuff, as I had to finish up the house I am building for my parents in NE. I got my truck from the dealership. Nothing changed - still slight surging, not quite right shifting it seems, and still crappy fuel mileage. I have now driven it about 4000 miles since the check engine light first came on in late September. I am not sure what to do, but I think I will take it back to the dealership here in Montana again. I am just not OK with a 75K truck suddenly having these issues, and losing about 20% MPG if not more, 9 months and 20K miles into ownership. It still works for me, pulls my job trailer, etc. But I wonder if I am driving a ticking time bomb either with the engine or transmission.
If anyone is wondering, I am vigilant keeping up on oil changes, maintenance, etc. I don't drive my truck very hard, but also don't baby it. I do pull an enclosed job trailer that weighs 5 to 6K lbs when full inside (it is usually very full inside with tools, materials, etc). But I don't think that is a rational reason to think that this truck has been used too hard, etc.
IDK what to do. I will likely be past 36 K miles in about 4 months. Drivetrain and engine SHOULD be covered up to 60K, and I also bought an extended warranty that is bumper to bumper up to 60K miles. I just don't want to chance having a truck that goes out of warranty without having these issues fixed by GM as they should be.
Arivers916
Member
What leveling kit do you run? Do you run UCA’s? Do you run premium gasoline as the truck requires ? It’s the same price or even a little more than Diesel :-( makes me regret the 6.2L sometimes.
I'd guess that if someone is saying "gas is cheaper than diesel" then they are running regular unleaded and not premium. Where I live, premium is approximately $.50 more per gallon than diesel. The premium requirement was one reason I didn't buy a 6.2.
Teegunn
Well-known member
I have the Rough Country 1.5" levelling kit and the RC upper control arms.
I usually don't run premium, but do sometimes. I have never been able to tell a difference in power, MPG, etc. So I don't see the point.
Wakinvol
Active member
Arivers916
Member
Yea i Hmmmmed and haa’d about the two and chose the 6.2 both had the new interior but I didn’t trust the less vetted 3 liter. Now if I traded it , I’d take a 10k$ hit atleast and I could buy a lot of premium fuel for that. So I guess I’m stuck with it. Lol
Wakinvol
Active member
I really liked my 21 Trailboss, but the mileage got on my nerves combined with the premium cost. I can say that the LZ0 seems to suit me fine. I got a really good trade ($50k on my 17k mile truck) saved a ton on my AT4 so it was hard to turn down. My daughter plays college hoops and I like to travel for road games, and the 3.0 just suits me. Hopefully it will last!
Diabel1969
Member
so far, I got a best of 25.5 with the 6.2 driving to Florida and back to Upstate NY
NCB_’22AT4
Member
2022 AT4 w/ 6.2…Supreme fuel since day it left the lot…Readylift level…295/70/18 Nitto’s…I’m sure tire size increase is the main culprit for mileage decrease…however, the 6.2 sure helps with the SMILES per gallon!!!
myrez
Active member
Curious what is considered Upstate NY.. Coming from a Buffalo suburb guy.
Is the premium fuel "required" new to the refresh? I have a '21 6.2 and it just says recommended, same as the wife's Acura, my coworker's F150, and seemingly every other newer car/truck in the past 5 years. I'm at 50k and run 87 octane 90% of the time. The other 10% is 89.
On the 50mi average I'm at 13.8 and best is 30.2. That is with DFM disabled and 60lb load E tires.
Diabel1969
Member
What suburb is that? I'd call you Western NY. I used to live in Auburn, and Syracuse many moons ago. But I'm from a little city northwest of Albany. I'm just north of Amsterdam, at the foothills of the Adirondacks.
I find it funny when city folks call themselves from upstate, when they're literally just out of the city
myrez
Active member
Agreed. Those weirdos say Buffalo is upstate.What suburb is that? I'd call you Western NY. I used to live in Auburn, and Syracuse many moons ago. But I'm from a little city northwest of Albany. I'm just north of Amsterdam, at the foothills of the Adirondacks.
I find it funny when city folks call themselves from upstate, when they're literally just out of the city
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