1500 mile review ( actually 1871 miles) :

Spent some time in the truck this past week, both on the highway and off pavement. Truck rides like a dream and handles nasty caliche roads like a champ. Because it’s so smooth I find myself driving faster on ranch roads, which has led to a few unexpected surprises when I hit a hog root or hole in the road. On the highway it’s like riding on a cloud.

I haven’t really got on the pedal too hard yet, but did have to accelerate quick one time to avoid a truck and the getup and go is there from a slow roll, at highway speeds accelerating is effortless.

Fuel mileage is fair, not great but not bad either. Considering the height of the truck and the tire size, it’s more or less a lateral from the other trucks I’ve owned that were similarly equipped. I’m getting around 15-16mpg on the highway with small towns and stops mixed in. Best I’ve gotten is 18mpg on a flat farm to market road.

Only thing I’ve towed so far is an empty 16’ flatbed pipe trailer. It’s not heavy @ 2600 lbs but you can feel it back there. It didn’t seem to pull quite as well as the Ford, but it does have a slightly higher gear ratio ( 3:42 vs. 3:55 ) so this may account for the difference. Will probably hook it up to a heavier load on the next week or so.


So far, been real impressed with the ride quality on and off road. Been a real game changer

That is a great looking truck. My wife has a new Denali and loves it, but I hate the GMC seats, the last two I have owned are the least comfortable seats I've ever ridden in.

They take some getting used to as they are much firmer than what you would think.

But, on longer drives, which I do every day, I find them more comfortable. Kinda of like a firm mattress, they are not inviting at first, but you get better sleep

I have a 2020 AT4. I have not heard of AT4X. What is different on an AT4X?

Different interior, different bumpers, different wheels/tires, multimatic DSSV spool dampers ( shocks) different ride height…basically it’s a Denali where they took out all the chrome and old man accoutrements and replaced it with more rugged off road geared options

Ok thanks for the info. Looks like all useful stuff added. I learned something today

also at4x aev edition= boron bumpers and excessive boron skid plates

They also have different upper/lower control arms and steering components. Supposed to be before for more off road use. Visually they look significantly stouter. IMO the IFS system was always a weak point with GM but we will see

They had an AEV edition on the lot. Looked good but for another $10k I decided to pass. A little to “bro” for me

heavy!! Think it has like 600lbs in skid plates. I could be wrong but pretty sure that's what I read

The AEV curb weight is somewhere around 8600 lbs....It does have steel bumpers but they can't be that heavy.

The Duramax used to be considerably lighter than the Ford but now the curb weights are about the same....I think the Ford Tremor is 7900# and the Duramax right around 8k. Listed specs are 7300# vs. 7700#......the AEV curb weight is 8600#....its a heavy SOB



Read an article in a Truck magazine that had a 0-60 time in the high output Diesel vs. the Duramax vs. the Dodge Cummins. Despite the considerable power difference, the Ford H.O only beat the GM by .3 seconds- 6.3 vs. 6.6 seconds. The Cummins hit 60 mpg after 8.1 seconds....considerably slower. The 7.3 Godzilla beat the Cummins by almost a full second. The Duramax did beat the standard option Powerstroke in the 0-60 times.

I’ve never needed to get my truck to 60mph in 6 seconds, not really sure why that’s even a notable stat for these trucks. That being said, my powerstroke was definitely faster than my Cummins, but the Powerstroke fell on its face when we had the boat or camper hooked up, but the Cummins never seemed to notice. Of course my Powerstroke was the hated 6.4 and not the newer 6.7, so that may very well have a lot to do with it.

How’s the AT4X doing?

The AT4X is very nice but I too do not like the AEV version as much. As a long time "person of the business", I see issues with future repairs. The whole front bumper is AFTERMARKET regardless if it's "OEM" new and some of the trim is different to match. This means in the future, you may not be able to get the bumper, its parts, or the other trim that is different from a regular AT4X. And the bumper IS that much heavier. It's thick textured steel instead of a sheet metal facade. The rear bumper is similar. The rocker guards (technically not steps) are about 3X the weight of the chrome 6" LPO steps. I know from picking up the boxes (they are dealer installed).

We have a volcanic red AT4X AEV 3.0 diesel in stock though if anyone has $80K to burn.

The stock front and rear bumpers are getting replaced with Frontier or Ranch hand replacements as soon as the manufacturers have them out. Too much liability going unprotected.

And yes, I didn't care for the AEV edition either.

The 6.4 diesel was a 700 ish ft. lbs of torque truck.not bad but nothing like what we have available now. Cummins sort of stopped trying to keep up with the HP and Torque numbers shortly after the 6.4 came out. the H.O in the 3500 model is impressive, but the 3/4 tons don't get the H.O due to the transmission.


I'm just over 5k miles on the ODO now and overall I'm liking it. It isn't as fast as my previous two power strokes ( the tremor would really move from 40 mph to 80 mph ) but its more than adequate. Ride is unbelievably smooth....hope that does not change when I add the level and front end...been hearing conflicting reports on the level messing with the DSSV shock settings and creating a rougher ride up front. we will see. Overall, when I'm in the truck for 4-6 hours at a time, I'm not wore out like I was driving the Fords.


Only big complaint is this thing is a Diesel Hog....14-15mpg is what I'm getting, If its level and I take it easy I'll get 17-18mpg but still, not great.

I’ve never seen a Chevy do well after changing the front suspension

if you're going to level, got to change upper control arm, IMO

The AT4X has different upper and lowers. Visually, they are much beefier than the ones that come on the other 2500's.


I had a 4" lift put on my 1500 in 2015. Changed the Control arms , but that didn't fix anythig. Wore out 3 sets in 80k.

Thats why I'm just wanting a level to take out the slight rake, now it's not all that noticeable but with the front replacement its going to be too much Imo.

Well, just found out that you cannot level an AT4X 2500. The shocks have certain settings that if exceed a certain height it will cause failure with the DSSV dampers. Basically, the AT4X is already lifted in the front ( and it is) and has enveloped all the ride height the shocks/control arms will allow. This is per ReadyLift, they are working on a level system right not but have not come out with one.


So....we are now looking at doing a reverse level in where we change the rear blocks to ones that are 1/2 " lower than the factory blocks. To be honest I wouldn't mind it being a little lower, its taller than my Ford in the rear and makes getting into it a pain, even pulling a trailer I really need to get longer drop hitches.

just get a dirtbox draw system and puts some tools in it

Last thing I want is more weight in that big bish

still a 3/4 ton truck, will ride better with a little weight back there. Put cool stuff like drones, air compressors, plug kit, etc

these even have built in slide for coolers etc.

https://dirtboxoverland.com/pages/truck-bed-drawer-system-info

I’ve been keeping my welder in my new one to help it ride better until we build a bed for it

And it makes me look like a pipeliner

Thought about a box system but then I would't be able to put 25-30 bags of feed in the bed, nor my water tote.

It rides surprisingly well for a 3/4 ton. Much better than my son's F-150 with a lift and 35's