2023 6.6 Gas Real World Towing Observations

SWDoodle · January 6, 2023

Took the new 6.6 gas on a heavy tow today. Had to haul some 6 weight calves to the sale barn. GCVW was just shy of 26K without me in it. We were maxed out! To give some perspective I live in Western Kansas and its pretty much flat. Outside of a few climbs in where some dry rivers are, it's pretty easy towing (this isn't the Rocky Mountains out here). I will say one thing I was impressed with how this thing did. I still have my 15 LML and love that pickup but this new 6.6 gas ain't no slouch either. I was mainly keeping it locked into 5th gear running between 65-70 and it did fine. Only downshifted to fourth a couple times on some small grades. One stretch I let it shift into 6th and it pulled it fine, but I kept in 5th most of the way just to keep tranny happy. The attached picture of the gauges on that 6th gear run. Never saw the trans temp go above 160 and had zero issues keeping speed. I think the 6 speed is adequate but it's a little doggy in the mid-range. The only flat spot in the power band is shifting into third and into fourth. Just kind of a dead area of power/torque. No issues on low end to get moving and once up to speed things are good. I think the new 10 speed will correct this. I do miss the exhaust brake though. That's probably the biggest issue. As far as mileage goes I was shocked. I pulled the calves 80 miles and computer said just a touch over 10 mpg!! Maybe I was just lucky today but that was impressive. My LML usually only does about 11 with this type of load. I have 5000 miles on now and seems like the engine is settled in as the mileage keeps getting better. Lifetime mileage so far is 13 and my LML is 14.5. Still love the diesel and plan to keep it around but I was smiling pretty big today with the performance of this 6.6. Hope this real world experience might help someone wondering about the towing ability. If GM got the hp up to 450 and the 10 speed there would be a lot more gassers being ordered I would imagine.

Pryme · January 6, 2023

How much do the calves weigh? How much is it per head in Kansas, for say 1k-1,200lb?

SWDoodle · January 6, 2023

38 minutes ago, Pryme said:

How much do the calves weigh? How much is it per head in Kansas, for say 1k-1,200lb?

Had 21 calves on the trailer weighed 640 lbs avg. I'd say 1000 lb steers would bring $1.70+ in this market. Pretty hot right now. If it ever gets to raining again out here be out of sight in 2024. Massive herd liquidation out west past year. We won't be able to hang on this summer if it doesn't rain/snow soon. Driest I've seen it in a long while.

NaturallyAspirated · January 6, 2023

Inspiring.

GM has gotten a lot out this motor.

77xbody · January 6, 2023

My GCVW of my 2500hd is 24,000 and I don't ever see my truck up at that weight but it's nice to hear that 6.6 doing ok that heavy. I hate to compare it to my old 6.0 but man it pulls and tows so much better

Doodle · January 7, 2023

9 hours ago, 77xbody said:

My GCVW of my 2500hd is 24,000 and I don't ever see my truck up at that weight but it's nice to hear that 6.6 doing ok that heavy. I hate to compare it to my old 6.0 but man it pulls and tows so much better

Yeah this 6.6 runs circles around my old 6.0 but it was also a 4 speed too. But those things were pretty much indestructible. I wouldn’t want to pull max GCWR all the time but it could do it. I’d still prefer my diesel for the heavy loads but it’s reassuring the gas can get the job done if needed.

Jettech1 · January 7, 2023

2 hours ago, Doodle said:

Yeah this 6.6 runs circles around my old 6.0 but it was also a 4 speed too. But those things were pretty much indestructible. I wouldn’t want to pull max GCWR all the time but it could do it. I’d still prefer my diesel for the heavy loads but it’s reassuring the gas can get the job done if needed.

Great info. I've got the gasser too and love it. It's so easy to live with. Just fire it up and go. Strap on a heavy ass trailer or camper and off you go...thank you so much for this post. I do love the diesels, don't get me wrong, I would love to have all that torque in waiting for my right foot to push down on the go pedal.....but this gasser is really something special....LOVE IT!!!

20SierraL8T24 · January 8, 2023

I ordered a 24 gas AT4 yesterday. We built it today at my dealer and it'll get submitted on the 19th.

I had a 21 L5P and it was nothing but check engine lights and I traded it on a 1500 6.2 while it was in the shop waiting on a def tank. My 2016 LML blew a HG, Coolant tank, 2 water pumps, and a DPF... I'll miss the raw power of a diesel but actually looking forward to the simplicity of the Gas truck with the 10 speed behind it.

I towed my 2755 Coleman travel trailer 800 miles and it was a white knuckle ride even with a WD hitch. I thought I could get away with it but it's just not safe.

Doodle · January 9, 2023

On 1/7/2023 at 6:27 PM, 20Denali22 said:

I ordered a 24 gas AT4 yesterday. We built it today at my dealer and it'll get submitted on the 19th.

I had a 21 L5P and it was nothing but check engine lights and I traded it on a 1500 6.2 while it was in the shop waiting on a def tank. My 2016 LML blew a HG, Coolant tank, 2 water pumps, and a DPF... I'll miss the raw power of a diesel but actually looking forward to the simplicity of the Gas truck with the 10 speed behind it.

I towed my 2755 Coleman travel trailer 800 miles and it was a white knuckle ride even with a WD hitch. I thought I could get away with it but it's just not safe.

Wow didn’t know the configurator was going yet. My dealer told me they hadn’t seen anything yet, but I did read somewhere the order banks were supposed to open Jan 19th. I was holding out for the refresh but when they switched to the 2024 I went ahead and bought the 23 last fall. My plans were to probably trade it off early for a 24 if the prices are insane. Did you ‘re dealer give yo any indication of pricing/options? I figure my 23 used will be worth a decent amount in 2023 I would hope. Guess we’ll see what the numbers look like and try to get some indication of when it could get built.

20SierraL8T24 · January 11, 2023

On 1/8/2023 at 9:49 PM, Doodle said:

Wow didn’t know the configurator was going yet. My dealer told me they hadn’t seen anything yet, but I did read somewhere the order banks were supposed to open Jan 19th. I was holding out for the refresh but when they switched to the 2024 I went ahead and bought the 23 last fall. My plans were to probably trade it off early for a 24 if the prices are insane. Did you ‘re dealer give yo any indication of pricing/options? I figure my 23 used will be worth a decent amount in 2023 I would hope. Guess we’ll see what the numbers look like and try to get some indication of when it could get built.

I told him what I wanted, he said I was good to go for the 19th. No pricing yet, just able to see the order guide and options on the dealers end right now. The configuration tool should be live any day now too

UWSkier · January 26, 2023

Any update to this on pricing now that the 19th has come and gone? Now that the 6.6 has the 10 speed, I'm about 90% sure that's my next truck.

@20Denali22regarding travel trailer with a half ton, there are some things you can do to make it a night and day different experience. Half tons come with squishy P-metric tires. Change to load range E. Put Roadmaster Active Suspension on the rear end. I spent the $3500 on a ProPride hitch too, which is pricey but worth every penny. I did a 4000 mile round trip last summer towing my trailer from AZ to WI and back via some mountainous terrain and winds in the plains. 5.3L and 8 speed did shockingly well. Super easy drive. Only thing I'd have liked is another gear between 3 and 4 on the climbs. If the 4k wasn't going to be an annual trip, I'd stick with half ton with the mods I mentioned.

nick112288 · January 29, 2023

While the 6.6 is rated more than capable for what I'm looking at, I also wouldn't complain if GM would develope that mystery big block that was rumored before COVID.

Especially not that Ford has the 6.8 and 7.3, and rumors are out there that Ram will have a 6.7L turbo gas Cummins.

Pryme · January 29, 2023

16 minutes ago, nick112288 said:

While the 6.6 is rated more than capable for what I'm looking at, I also wouldn't complain if GM would develope that mystery big block that was rumored before COVID.

Especially not that Ford has the 6.8 and 7.3, and rumors are out there that Ram will have a 6.7L turbo gas Cummins.

The 6.6 gas already dynos right with the 7.3. So the 6.8 they are offering with the base truck, which is a dumb idea and only good for ford to boost higher trim sales, is not even close. I also read it doesn’t even have a forged crank.

Jettech1 · January 29, 2023

2 hours ago, Pryme said:

The 6.6 gas already dynos right with the 7.3. So the 6.8 they are offering with the base truck, which is a dumb idea and only good for ford to boost higher trim sales, is not even close. I also read it doesn’t even have a forged crank.

I haven't read anything about the ford engine but I do know having an iron block, with 6 bolt mains, with a forged crank and forged rods is nothing but the best bottom end ever!! That 6.6L is amazing. I'm hoping GM ups it to 450hp and say around 510 torque. That is well within what the 6L90E can handle and makes more sense using more of what the actual capabilities of that engine and drivetrain. The 11.5" rear end will love it too. I'm curious as to why they derated it so much, and all I can come up with is fuel mileage. Because hyping it up making more hp and tq, will have no negative effect on the overall drivetrain.

64BAwagon · January 29, 2023

I am hoping that GM finally does something about the weak torque converters they are using. I cant imagine a billet unit being all that much more expensive. If it was a lone problem, that would be one thing but a TC failure wipes out the rest of the trans. If I keep my 2021 past the 3/36 warranty I will likely bite the pillow and have a billet TC put in it.

Of course this is the same company that cheaps out on tapping a 1/2" pipe plug hole into the bottom of the rear diff so a job that could take 15 minutes turns into an hour.

Edited January 29, 2023 by 64BAwagon