towing with gm 6.6 gas

[jffnkrn]

Well, just info please.
just real experience please.
Anyone towing with GM 6.6 gas, 3:73 or 3:42?
How do you like it? performance with and without trailer?
maybe change for me, I have 14k fifth wheel, I'm not going diesel.
thanks

[MNRon]

Some older data that doesn’t directly apply, but I pulled a 9k TT with a 2002 8.1gasser for several years. It never bypassed a gas station, I got ~7mpg towing. Pulled fine on flats, and OK on small hills; got stuck slowing down on a pass for a trucker and could never climb back above ~15mph while the engine screamed all the way up the mountain out west.

Replaced it with a Duramax in 2013 and you can’t wipe the smile off my face as I pull our 16k 5er now with ease across the Rockies or wherever I want to go. Get 10-11mpg and even pass gas’s stations now. Haven’t seen any comments on the exhaust brake on diesel’s, that’s worth the price of admission by itself in my opinion.

[jffnkrn]

IdaD wrote:
Gas HD towing any kind of heavy-ish high profile trailer is going to be single digits unless you only tow downhill with a tailwind.

IdaD, I don't want to sound sarcastic, but i get single digits towing downhill with a tailwind anyway!!! and most of the time I get headwind even downhill. so UGH on that, Thanks though

[IdaD]

Gas HD towing any kind of heavy-ish high profile trailer is going to be single digits unless you only tow downhill with a tailwind.

[cmarkj]

We have a 2500HD with the 6.6 gas. We haven't done a whole lot of towing yet but we have done a trip from northern Illinois to central Kentucky last spring and a few trips to different places in Wisconsin. Trailer is roughly 7500# and at 62mph on the highways we are getting 8.5mpg on avg. i"m very happy with that considering that's what I was getting with my Tundra.

[Dadoffourgirls]

Some stats -
I drove 16324 miles, Avg 13.0 mpg.
459.1 total hours, 79.6 idle.
1308 gooseneck towing miles, 8.2 mpg
Brake pad life - 96% F, 97% R
203 travel trailer miles, 8.2 mpg

[Sjm9911]

Ok , that was rude of me, apologies. I was responding to anothers post. I did also state that my camper was way significantly lighter then the ops and the op would have vastly different results. Thats why I put my tow weights into the response.

[rhagfo]

Sjm9911 wrote:

jffnkrn wrote:

Fishbreath wrote:
I have a 2022 6.6 gas, 3500 CC, SRW. As stated above, it only comes with the 3.73 gears, no 4.10. I was a little worried about this, but I am please with performance.
I do not tow a heavy trailer. To date, I have towed a 7.5k travel trailer and it towed beautifully. The "tow" mode keeps the transmission from hunting and it is very quiet. Gas mileage is 14 mpg, compared to 10.5 for the 6.0
The new truck is significantly quieter than my 2019 3500 with the 6.0.
If you have specific questions, send me a PM
Bill

yeah but what is the mileage difference when towing.

On my TT thats a bit lighter then his 7.5k camper I get 12 to 13 mpg. Not much difference loaded or unloaded for me. For you and a way larger camper, it will be much diffrent. I think my TT is around 6k/6.5k lbs loaded.

Well the OP is looking at towing about twice the weight and about 4’ taller trailer than you two, apples to oranges.

[Sjm9911]

Grit dog wrote:
^12-13mpg avg towing a TT sounds pretty optimistic, what avg speed towing?

Im not getting into it with you dog. I posted last time the shots of the 14 mpg I normally get driving on the last thread. 65 mph. And its not optimistic, its real. I have had the truck and camper together since early 2020. Did about 4500 miles towing last year. Probably the same the year before. My 3012 sierra 1500 I got 8 to 9 mpg. Its not a heavy camper. Tbh, it handles way better with the weight behind it.

[Grit_dog]

^12-13mpg avg towing a TT sounds pretty optimistic, what avg speed towing?

[Sjm9911]

jffnkrn wrote:

Fishbreath wrote:
I have a 2022 6.6 gas, 3500 CC, SRW. As stated above, it only comes with the 3.73 gears, no 4.10. I was a little worried about this, but I am please with performance.
I do not tow a heavy trailer. To date, I have towed a 7.5k travel trailer and it towed beautifully. The "tow" mode keeps the transmission from hunting and it is very quiet. Gas mileage is 14 mpg, compared to 10.5 for the 6.0
The new truck is significantly quieter than my 2019 3500 with the 6.0.
If you have specific questions, send me a PM
Bill

yeah but what is the mileage difference when towing.

On my TT thats a bit lighter then his 7.5k camper I get 12 to 13 mpg. Not much difference loaded or unloaded for me. For you and a way larger camper, it will be much diffrent. I think my TT is around 6k/6.5k lbs loaded.

[Dadoffourgirls]

I had a 2020 Silverado reg cab dually. It was one of the first with the 6.6 gas. I had it for 14 months, and towed gooseneck trailers with 14 hay round bales, and my travel trailer. It towed wonderfully in Michigan. I never had a chance to tow anything out of Michigan.

I did have one point when towing the 15k hay trailer, that was uphill from a traffic stop. And I had the stop each time. The truck did great.

I have towed the same with the new Duramax, and yes, it is better. I had no issues with the gas engine.

[Grit_dog]

Fishbreath wrote:

Grit dog wrote:
^You mean 14mpg empty, right?

Of Course!

Haha, I presumed that as well. But you’ve seen some of the “mileage masters” post their other-worldly fuel mileages before I’m sure.
To be fair, the 6.6 should be and seems to be on par with the other mfgs offerings. The 5th gen LT engines have been around for a while and should be solid if GM is advancing that engine line into an application that will be in much greater numbers than current offerings in the Vette (and Camaro?).
That said, I wouldn’t buy one if I was in the market for a HD gasser as GM is shorting the customers on advancements and technology compared to the other 2 mfgs, by cost cutting and slapping a 15+ year old transmission behind it. That’s a move usually reserved for the bean counters over at Dodge/Ram. Lol

[jffnkrn]

Fishbreath wrote:
I have a 2022 6.6 gas, 3500 CC, SRW. As stated above, it only comes with the 3.73 gears, no 4.10. I was a little worried about this, but I am please with performance.
I do not tow a heavy trailer. To date, I have towed a 7.5k travel trailer and it towed beautifully. The "tow" mode keeps the transmission from hunting and it is very quiet. Gas mileage is 14 mpg, compared to 10.5 for the 6.0
The new truck is significantly quieter than my 2019 3500 with the 6.0.
If you have specific questions, send me a PM
Bill

yeah but what is the mileage difference when towing.

[Fishbreath]

Grit dog wrote:
^You mean 14mpg empty, right?

Of Course!