UWSkier

Depends where you're going to be towing. I have a Grand Design 2600RB, which we roll heavy when we go cross country. Into a wind above 5000 feet elevation, it struggles to keep the RPMs down and gets absolutely abysmal mileage. How fast do you like to drive? The truck handles the trailer beautifully, and the engine is great below 2000' in nearly all conditions.

Interesting the LTZ is gone on the 1500s. That's a super popular trim level on the 2500s. Most of the goodies from the HC, without the price tag.

There's also this one if your truck is like mine and started having really hard upshifts from 7th to 8th gear. https://static.nhtsa.gov/odi/tsbs/2024/MC-11010466-0001.pdf

Michigan to Alabama is pretty low and flat. You'll be fine. If you lived in the west, I'd encourage a trade. I tow a smaller TT than you do and wish I had the diesel above 6000' elevation or in strong winds.

Didn't change the ride on my half ton Denali but helped with handling a ton when loaded.

I put those on a half ton Denali to help with towing a 30' travel trailer and they helped a ton. Just don't crank them up too high or your truck sits like a dragster unloaded with the rear up in the air.

That's good if it works for you. I just did a 5000 mile tow of my 8000# travel trailer cross country, and the only time I'd turn mine on is if there were lane closures that had us down to a single lane and I wanted to keep a large distance. If I use it during regular interstate cruising, I find it's constantly hitting the brakes when people pass me and move back to the right, or if I'm in the left lane to pass a line of slow cars, it leaves a big gap and people keep cutting in front of me, slowing me down, making everyone think I'm the left lane bandito. It leads to people passing me on the right. It's a bit too cautious in tow/haul for my liking.

There's a recall for the 2024s where they replace the TBCM with an updated unit. The fix was originally to put in a 2023 module. But last time I had my truck in, they said there was ANOTHER recall on the 2024 TBCM and swapped my module again. I've towed my RV 6000 miles since then with no brake issues, though I did also install a diode in the line to kill the problem. In the 2024s, the issue was that the TBCM just decided to disconnect the trailer brakes any time the voltage on the trailer exceeded that of the truck. If you have LiFePO4 batteries and a charge controller for them, you're likely occasionally pushing voltage back to the truck rather than the other direction from the alternator. A diode from the trailer to the truck fixed the issue for the 2024s. Surprised to see this happening on a 2025.

In the Mercedes, I only ever use adaptive cruise. In my Silverado, I hate it and disable it (since I'm usually towing). GM's implementation is crap compared to more refined brands.

Only time I use it is if I'm towing the RV through a construction zone and want to maintain a big gap between myself and the vehicle in front of me. Rest of the time it's regular cruise. The algorithm on the GM HDs sucks for adaptive cruise. My wife's Mercedes is a million times better. I like the cruise on that thing. You barely notice it, and it will keep a close enough distance you rarely get cut off.

apples to hand grenades, but I was running the factory Michelins on my truck down around 50/45 F/R for several months and they started getting loud. Put them back up to factory spec before the 2500 mile RV tow back from East to Arizona and they got much quieter after the first 200 miles. I like the ride with them softer, but the noise got on my nerves. Think I'll keep them 55/55 or thereabouts for non-towing.

Why parting with them after so few miles?

Would like to try them but it's a bit more than I want to spend on an experiment. Hoping to see some more reviews of them first. Biggest issue I have with the Ranchos is the rebound damping. They have all the rebound control of a pogo stick.

Gas is the right choice for me other than the 2 camping trips per year when I have to pull through mountains exceeding 6000 feet in elevation. But yes, the truck is the camper puller, and once we get somewhere, it's the grocery getter, running errands vehicle. And below 2000' elevation the gasser does OK, not great with the TT. It 100% depends on the wind. Crossing Kansas on the way East in July with tailwinds most of the way, it got 9MPG and loved running in 8th gear. Crossing NM... was mostly in 6th and 7th.

Just did the tow through NM to eastern AZ in strong winds today, with an 8000 lb travel trailer and going the speed limit of 75MPH. The tach barely got below 3000 RPM once today other than coasting downhill into ABQ. I know it's built to rev like a mother, and I let it do so in the climbs. My wife is always saying I'm abusing it, and I just tell her the engine is overbuilt to handle that sort of workload... but I'd get a diesel if I was buying again tomorrow. I had higher expectations of the gasser with the 10 speed. I figured that transmission would be a great addition to the 6.6L gasser, but the thing just skips the in between gears most of the time anyways. Like if a climb ahead of you looks steep and you kick it down from 7th to 6th ahead of the hill to get it into the powerband, it'll never stay in 6th. It just drops to 5th and revs to the moon unless you are willing to scrub momentum. It has plenty of grunt to pull the hill in 6th but it'll always choose to rev vs grunt. I used to do this pull with a 2016 5.3L with the 8 speed and that would rev like crazy too, but TBH, it wasn't really any less capable of keeping the load moving. The only place I really notice a difference between the 6.6L and my old 5.3L is getting the load moving at a red light. This engine is begging for forced induction.

Ecoboost will maul the 6.6L in the hills, then need a complete teardown in 60k miles. The 6.6L is a stout engine, but it's underwhelming power-wise.

Only managed 17.5 on the dash computer today. I wasn't lead footing it. It was windy, not all tailwinds.

I've gotten 19+ before, but it's not typical. I have a drive from northern WI to Appleton tomorrow which is mostly 55 mph roads with small towns. Wind should mostly be at my back. Will be interested to see what it returns on that drive as it's also about a 1000 foot descent over the 2 hour drive.

I did the same thing. Been working well for a few years with this setup and seems more reliable than the standalone setup I had before that would occasionally false alarm.

My understanding is the "Allison" 10 speed shares nothing with the 10 speed in the half tons, which was co-developed with Ford. As for the original question, the 10 speed in the HDs shifts beautifully when it's working right. Mine's been to the dealer a couple times to fix a hard shifting issue. Hoping it's solved for good.

I know this is an old thread, but I'm at 21k miles on mine and I have a noticeable differential whine when on the power. I may also have a driveline vibration at 75MPH but I think that's a harmonic thing with the tires as it doesn't seem high enough in frequency to be rotating with the driveshaft. I have about another 500 miles to go in this cross country camper tow I'm doing, then it's back to the dealer... again... I bought this truck to tow hard and heavy, and it does, but for it to have so many driveline issues in under 25k miles is awful.

Yes, it's that bolt. I tightened mine like Chuck did too. Pull the bottle up tight to the fender and crank that sucker down. Sound gone.

Thank you! Back to the dealer tomorrow for this.

Actually, not really centered, just not making noise because the bottle can't move anymore.

Update: IT'S BACK! This will be my last GM. It has the ride quality and gas mileage of a 1938 Panzer and about as many rattles too.