GMC AT4X - Diesel or Gas?

[Andystoy AT4]

With ppe they have a bigger oil pan that can hold 2 more quarts of oil. I mean that would help with engine life no? Mind you it will help with longer oil changes. Also you didn’t mention which engine you have?

I have the LM2 R and oil changes are 7500 miles approximately, how far do you want to go on an oil change? Yes the 2 quarts will extend your oil change but not much else, your engine oil temp will take a bit longer to reach its temperature but it will still operate at the same temperature. What is the expected payout?

 

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[TX_Critter]

I’ll add my 2 cents:

Just got back from a long road trip out west (3500 miles in 9 days) through NM, UT, CO, and NV and my 3.0 dmax was flawless. On the interstates running 80+ I averaged 23-24mpg and on the smaller highways (55-65) saw as high as 30mpg. I put one box of DEF in during the trip but it wasn’t quite full to start, probably used a total of about 4 gallons.

My 50 mile best mpg is currently over 40mpg from coasting downhill on Monarch pass in CO lol.

There are issues with both engines, lifters and dynamic fuel management on the 6.2 and emissions crap on the 3.0… just have to pick your poison.

 

[TX_Critter]

For regens can you just let it sit in your driveway if you don’t make the full regen? Or do you have to be driving for it to do the full cycle?

I got a banks iDash to watch when the truck goes into regen and have learned a couple things.

It likes to have load on the engine to keep exhaust temps up and burn off the particulate filter, but it can pause a regen and pick it back up if you shut the truck off or don’t put enough load on the engine. It has to be at operating temp before it will start again though.

It has never happened to me but I have seen others say that if you pause too many times it will put a message on your dash to keep driving so it can complete the regen cycle, so long as you listen to the truck I don’t think there is too much to worry about.

 

[Cocoabean]

For regens can you just let it sit in your driveway if you don’t make the full regen? Or do you have to be driving for it to do the full cycle?

no, I dont let it sit and idle for regen. I just make sure my next drive has some milage to it. Its really never anything you need to worry/think about.

 

[mocomajek]

I have a 22 AT4 refresh with the baby Duramax. I've got over 12k miles and no complaints except the tires roar a lot more than I expected. It came with the Goodyear MT's. I absolutely love the fuel mileage. The best fuel econmy over 25 miles is 39mpg and 50 miles is 36.9. I came from a 2017 F150 (5.0) and would barely get 350 miles to a 24 gal tank. I'm getting close to 600 miles or more on this 24 gal tank. Also, from what I can tell, a full tank of DEF goes about 5000 miles, give or take. I'm getting much better price per mile on this DSL then I did on the F150 gas burner for sure!

Couldn’t have said it better.

 

[poopster]

Couldn’t have said it better.

Yea, but around this area, Diesel is $1.59 more a gallon then regular gas.

 

[slythetove]

If the 3.0 had been an option when I bought my AT4 I’d have likely gone for the AT4X. I had a buyback on my first one and still replaced it with another one. The diesel is awesome.

 

[nabatron]

If the 3.0 had been an option when I bought my AT4 I’d have likely gone for the AT4X. I had a buyback on my first one and still replaced it with another one. The diesel is awesome.

What was wrong with it?

 

[Mcquojo]

I have a 2021 1500 3.0, running 285/75/17 with 95,000. I drive, a lot. A little over 40k a year. All Highway. I average about 21mpg, but if I keep my foot out of it I’m around 25-26. I absolutely love the diesel. Plenty of power off road, on road and towing. I don’t tow often, but I maxed out
the tow capacity hauling rocks. No issue pulling the dump trailer

I came from 2012 5.3, with 295/70/r18s. The 5.3 felt underpowered off road up hills and towing. The gas mileage was terrible. I will never go gas powered again.

The only issue I have had with diesel, was a check engine light popped on. It stayed during that trip, but reset itself the next time I started the truck. Dealer scanned the truck and didn’t find any codes. Oh, I’ve also had the power mirrors being finicky, dealer replaced them.

Buy your DEF from the pump! Some stations have a small nozzle. I found it at a chevron station with diesel truck pumps. Much better than those stupid boxes.

 

[slythetove]

What was wrong with it?

If you read through this thread and especially all my posts throughout it I outline the main issues and process I went through all the way from 1st truck to second with the same issue.

2022 Refresh AT4 1500 Duramax 3.0 Diesel Check Engine Light and Exhaust Leak

So I picked up my 2022 AT4 refresh on June 21st. All was well, no issues, ran like a tank. On July 6th the check engine light came on and I received an email alert to service the emissions system. I had only put one tank of fuel in it after going through the tank the dealership put in it. The...

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[AcclThrls4Xtrm]

For reliability get gas. Tried and true 6.2l is a GREAT engine. The fuel economy are almost negligible due to diesel and def $$. Range is a different story. When towing youll be filling up a bit more with the gasser...