It’s called Grade Active Braking. With GM trucks you won’t get the full effect of the exhaust brake until the truck senses you need it especially on a down hill grade. I personally think it’s nice not having the truck jerking you around with the exhaust brake every time you left off the accelerator or touch the brake pedal. Not to mention the possible increased wear on parts when it’s engaging but not needed. But to each his own.

For the exhaust brake to work: 1. Have Tow Haul mode on, 2. With cruise control activated, the truck will do everything for you, 3. Tap the brake if you want it to activate. Yes make sure the tire pressure is at GM spec.

The engine braking on the Cummins is second to none!! I'd rather have instant feedback, when I take my foot off the pedal, than having to constantly hit the brake pedal!

Please turn on tow-haul mode activate exhaust brake and enjoy the drive. Your truck will slow down using the trans and exhaust brake with regular braking as needed. Aa a owner of my own 3500 HD Duramax towing a 30' travel trailer it is a must that the exhaust brake and tow haul mode are on at all times while towing . Your owners manual will help you with when and if you need to use tow haul mode based on weight usually less than 75% capacity. If you have to stop hard ( emergency braking )you will be glad you have all of the above mentioned activated regardless! Safety is paramount ! enjoy your videos!

Always great information 👍🏾

I'm in the same position as you, just picked up my new 2023 GMC Sierra 2500 Denali Duramax a week ago and have much to learn. My previous tow vehicle is a 2012 F-250 PSD. Much to learn about this amazing truck. Unfortunately with the cold and snow arriving early up north, my first camper tow with it will have to wait several months until spring.

Just completed a 1750 mile trip with our 2022 GMC 3500HD Denali pulling our 19000lb 5th wheel. Got 8.2mpg average for the trip. Was wondering about the exhaust brake as well but really saw it in action coming down AZ87 into the Phoenix area.

Thanks for another informative review brother...

I had a Ram 2500 on order. I am hoping to pick up a Sierra 2500 tomorrow. Seeing you switch from the Ram gives me peace of mind as I’ve been watching your videos for a while now. Also, it’s ironic you mentioned the Ram transmission temp considering their recent recall. That recall froze my order 😅.

If you want the most from GMs exhaust brake, use tow/haul while climbing hills, turn off tow/haul and activate the brake while descending.. use brake pedal inputs to adjust .. it actually works really well and lets the driver decide how much braking is needed where ram just gives you all or nothing, often requiring you to throttle out of the brake or turn it on/off

I use the exhaust break on my Ram all the time even when I’m not towing. Works great, doesn’t have to be in tow haul mode or on cruise control. Just turn it on! Great on hills and the highway and of course saves the brakes.

From that side view while driving at the start, you look perfectly level!!! I have the 8 foot bed.

Looks so good

Hey JB, I towed with my 3500 AT4 today, and I must say, for a "consumer grade" truck it did pretty good. I mean, my expectations were low for a "consumer grade" truck. But I must say, it was really strong and comfortable. And the cameras, wow, never would expected the quality on a "consumer grade" truck. And then to find out it has an exhaust break, whaaaat, no way, "consumer grade" trucks aren't supposed to have that. Man I'm just busting your chops on the "consumer grade" comment in one of your earlier videos on the GMC. But seriously, I have towed thousands of miles between 3 of these trucks and you need to get used to a little different thought process. With the V8 you gotta get those revs up for the exhaust brake to work, and it won't do nothing unless it needs it. I tested it today, tap the brake on decent, get the Allison to drop a gear, get the revs up to 2500 and the exhaust brake will damn near stop you. Anyway, I hope the RAM fan boy can find some happiness in the "consumer grade" GMC. Lol

Hey brother, I am not a tire expert but I did notice a massive change in our rig based on the tires that were on the truck. We started with the Transforce, then Michelin, BFG KO2, and now the Copper AT3, I think. The cooper feels like they allow the rig to wiggle and twist, but the ride is 1000 times better than the other tires. I think the sidewalls are softer. I say this to say, it may not be the truck that is blowing around, but the tire sidewalls allowing for flex. We got used to the Coppers, but the Nexen seem to be a great middle ground.

Not sure what your tires are aired up to but I keep mine at 80 psi when towing. Reduces/ eliminates tire squirm and that feeling of the truck moving around.

Justin, you highlighted a lot of the features I appreciate on the GMC for towing as well. This truck is built for towing in my opinion. That black AT4 does look good with the Cougar in tow. This is my first diesel truck and the first time having an exhaust break. When I have used it going to Devils Backbone in the mountains it appeared to work really well. I need to be more conscious of it when I use it while pulling to make a good assessment of it. I did realize that not having the truck in tow haul mode does not allow for it to work. Looking forward to your follow up video to see what kind of Mpg you got. We just returned from Key West, Florida and we averaged around 10.6 MPG while pulling around 11000 Lbs. my average speed was around 62 because I am always trying to maximize my fuel economy.

Sick setup

Love it 👍

I’ve owned both GM and Ram HD trucks. Both great capable trucks. My only criticism of the Ram is the aged body design. Getting on 20+ years without any significant change.

What him said, just tap the break exhaust break engaged.

Honestly I think for exhaust braking between the two it comes down to the V8 diesels need to rev up higher than an inline 6 to get the same amount of back pressure. Now I have a 2021 Chevy 3500 drw Duramax and I've got a Banks idash gauge on it with the turbo vein position showing. I've noticed when going 65 mph in 10th gear the exhaust brake does come on and closes the veins 100% but the engine rpm is only running about 1650. When the truck is down shifting or you manually down shift the truck if you go over 2000 rpm the turbo veins start to open back up from 100% closed, so when I've had the rpms at 3000 with exhaust brake going I've seen between 89% - 92% closed based off what the truck senses. Over 3000 rpm the turbo veins continue to open from 89%. I think if GM would leave the veins closed 100% up to 3000 rpm it would make a big difference in exhaust brake performance. Maybe that'll be the case for the 2024s coming.

Good video JB! The exhaust brake is a definite con on these….. I have the 23 Denali also and just did some video on it.. It tows well but I do rate it number 3 as my confidence in stopping. This is the brakes and exhaust brake. I feel like my fords and Rams provide way more confidence. I have set a bigger gap in front of me with the gm for sure.. The acceleration and shifting is great.. I just did a review on the derringer and it definitely makes a huge difference.. Really looking forward to my 23 Super Duty..

Some other things I've read , the GM WHEN IN TOW/HAUL MODE SYAYS LOCKED IN 7TH GEAR WHICH IS 1:1 MEANING YOU TOW WITH STRAIGHT 3.42 GEARING

Having towed with the new Ford Superduty, how does that exhaust brake compare to the GMC? I like my 21 F-350's exhaust brake but I came out of an 08 Superduty, no exhaust brake, and with a 5 speed trans, so this truck is like night and day by comparison.

Interesting. I have found the exhaust brake on my '22 is so aggressive that I generally have to accelerate several times down all but the steepest of grades. It does require one braking event at the top and then its feet flat on the floor.

Jb, go to amsoil website and order a case of their all in 1 diesel treatment, run it everytime you fill up..

Truck looks great brougham. Yeah it has some minor cons but I like the gmc over the ram. That’s just me. I’ve never owned either, but if I was going to buy one it would be the gmc

Yep GM uses the best tires of the big three. 87 PSI in the rear tires is a bit aggressive I think (almost 9% over rating). Have a look in your myGMC app what the recommended pressure is, Shows 60PSI front 80PSI rear in the app for my 3500HD, definitely wouldn't push it past 80, It probably crept up there as they warmed up. I'd rather have it just under than go over the manufacturers rating for that tire, ESPECIALLY towing with your family. Also.. avoid running underinflated or you will see (literally see visibly) sidewall indentations/undulations... more a visual thing due to the tire construction than a performance or safety issue. Thanks for the video - stay safe!

Look into Lasfit lights. I upgrade all of mine on Silverado 2500 and man it’s a damn light show lol

ONLY my opinion , I think after sometime driving and towing the ALLISON'S TCM will learn how to slow the load down more efficiently with the exhaust brake activated , I guess we'll see in the future

I have a question for anyone to give their opinion on, which is better to tow a 5th wheel with a gooseneck or the standard 5th wheel hitch?

I'm awaiting your fuel mileage numbers after your truck is broke in to compare to my 22- 3500hd gasser. I talked myself out of the diesel, but my fifth wheel is about 4k lighter than yours so it may not be a fair comparison. Right now my truck isn't fully broke in yet and I'm getting about the same mileage as you are. We are still figuring out the loading configuration to keep us legal & safe. I told my wife it will probably take 6 or 7 stops to the Cat scale to get it nailed down properly. I don't understand how the truck manufacturers expect you not to never overload their trucks at all until you get your weights figured out. The RV manufactures do a terrible job of giving you the real weight numbers , so you have to weigh it yourself and go from there. Great content JB, keep the videos coming.

Dang bro I don’t know. If I spend my hard earned cash on a new truck that cost this much I want to be wowed by the features I don’t want to have to get used to living with them lol! The ridge grappler‘s you had on the ram weren’t necessarily my favorite all-around tire but I will say their stiffer side wall made them a better towing tire. I think that might be some of the sway issues you’re having with the AT4. The side profile of your rig is 🔥🇺🇸💪

I really like the exhaust break on my RAM 2500, I have it on regardless of towing a trailer. JB what’s up with the latest RAM recall on the transmission? I’m starting to wonder if RAM is worthy of my hard earned $$$$!

Should I order a 2024 GMC 2500 or 3500 AT4 6.6L V8 or 6.6L Duramax? Which one has no recalls and zero problems?

I know at least with my 2020 Chevy 2500HD with the exhaust break on if you tap the brakes and let off the exhaust break will activate.

The convex is power. You have to hit the mirror button 2x

Maybe you could have your VGT TURBO RESCALED FOR THE EXHAUST BRAKE , I DONT KNOW FOR SURE IF IT CAN BE DONE BUT MAYBE , ASK GM TECH 2

That's why we, in my family, call them good-for-a-years. Garbage tires. As for the sway -- get an alignment. Every new vehicle, always get an alignment. Maybe that's it, maybe not, but I always get an alignment asap on any new or new-to-me vehicle. I don't think I've ever gotten a new vehicle that wasn't out of alignment at least a little, had a few that were out a lot. Seems to be more of an issue on trucks than cars.

I had 2014 2500 6.0 gas , and I pulled 36,000 of salt bags no problem.

Have you thought about a lift kit?

Great video have a Great time in Moab? 😃👍

curious - if towing on a relatively flat road, do you get better mileage by not being in tow haul mode? or does it not matter?

All the groups I'm in saying the fuel mileage sucks on the new 23s after the ecm updates.

You’re wearing me out with this squat! Every time you ever measure a GM compared to the other brands the difference is negligible in either direction (in favor for the GM or worse for the GM). Measure the front to rear rake with no trailer and you will see the GM trucks are nearly level. The other brands, especially Ram are not. That is why you look more squatted than you actually are. Lol. Think of your Ram after the level kit. It looked much more squatted than before when in reality it was the same. As for the exhaust brake, again cruise control and tow/haul when you’re on roads like that and you will never tip the gas pedal or brake pedal. Now if you insist on not using cruise, then when you want to start down a grade you’re going to have to hit your brake a little and then the truck will grade shift with you. The problem doing that is you may end up shifting down too much and then you will go slower than you probably want to. So believe me. Cruise control on those types of roads. If it’s a road you can’t use cruise, then you’ll have to just tap your brakes when you want to slow down a little to make the transmission down shift. With all that said, it’s not going to be like the Rams because it is better. The truck looks good with your trailer.

Yeah I don't get GM's exhaust brake thing. I have a 21 Silverado 1500 with the 3.0 Duramax and I have to be steady on the brake to even get the exhaust brake to work, and I can barely feel it then too. They need to reprogram these things for sure.

I don’t know if comparing transmission operating temperatures is a good indicator of towing ability. Each transmission has differing operating temperatures. For instance the 6r80 in my f150 runs close to 200 degrees all the time, and will creep to 220 when towing. This is the specified range from FoMoCo.

I came from a 2017 Ram to a 2020 Denali 2500. I’m struggling a little bit with the transition. The Denali rides 1000x better, I think looks better overall, and seems to have more power while towing. However, the GMC exhaust brake is nowhere close to the Ram, the Ram steering was better (GMC very heavy), and overall comfort on the Ram was slightly better. Curious what your opinion is on just overall driving comfort on the GMC vs your Ram, I’m finding my GMC very “fatiguing” to drive.

2023 denali 3500 duelly had 2021 laramie duelly liked ram better exhaust brake a lot better gmc steering very vague

Should have water for 2024 model JB. Cheby finally upgraded the durtymax 😂

So TELL ME Ram or GMC?? I'm looking for ranch work truck so I'll be towing normal ranch equipment. Lumber, fencing, concrete, tractor, corn etc

JB, I'm trading in my 22' Ram 3500 Limited Cummins tomorrow for a 22' Ram 2500 Laramie Night Edition, 6.4 Hemi w/4.10s, Patriot Blue. I had ordered a 23' High Country Duramax, but with diesel prices, I just didnt want to spend that kind of money right now. I really wanted to order a 23' F-350 Lariat with the black appearance package, but it is not available to order until spring or summer next year, so that influenced my decision. I wanted a 6.4 Laramie Night with 4.10s and I could only find 2, both at the same dealership up in Fargo. They had a billet silver and patriot blue, both optioned the same, so I chose the blue because we know that in a night edition is sweet! I just can't put myself behind the wheel of a GM truck.

Man, all the emissions crap is killing the diesel fuel mileage, they’re only getting 2-3 mpg better than gassers. When you need that power though it’s a mute point.

Man you want to gripe about some sway while pulling a trailer lol try driving a tanker truck at max weight of 81k lbs off road in the mud, snow, ice 🧊 to the oil fields and see how a truck handles

SWAY ? YEAH GM TRUCKS WITH SRW DO SWAY , CURE , HELLWIG BIG WIG REAR SWAY BAR , WELL WORTH THE MONEY

I drive a 2020 Denali Duramax for work. I own a 2019 Ram Cummins. There’s no way I’d ever trade for the GM. The difference in torque when towing and security when towing is really all I care about. GM may look nicer and have cool features… but for me, doesn’t outweigh.

$1500 bucks and you can get an exhaust brake. Now you know the difference between variable gate (change volume of turbo) to variable vane (change pitch of vanes). GM trucks are not properly sprung for towing. They target the wife with a smooth ride.

On my fords 15+ and 11 duramax you have to let rpms get around 3500 rpms and she will work beautifully. I personally like the way GM and Ford tow better than ram hands down 20k+ trailer weights. That's where you separate the trucks. Under that weight they all tow the same and its just more brand loyal choice. Come to NC and we will hook that GM up to 24k and compare to my 22 f350 srw up 8% grade

I changed to GMC already!

No overdrive ,in tow haul

You have a 5th wheel. Why do you still have a hitch ball in, not allowing you to get the full use of your tailgate?? Seems useless.

You should have stuck with the RAM

Terrible interior. 24 looks little better but not to rams quality yet

Ram has a much better steering than the others , I have a 1977 Short bed Power wagon that I can run 75 mph down highway with 1 finger on the wheel they have always drove good

I have a SRW 1 ton Denali and the exhaust brake is basically non-existent… Also, I wish the display actively showed what gear you’re in.

Problem is all that junk on that Chevy will be in the junkyard before the Cummins gets broke in 2006 Ram 3500 535,000 miles and runs great