GM 6.6 gas

[LITEPHIL]

Not much talked about here on the new GM 6.6 engine. Whats the thoughts from people that own one? I may be interested in getting one next year if it has the 10 speed transmission.
Wish there was a bit more published testing other than those two guys that don't seem to really know what they're doing. Please don't refer to them since the test they did mentioned that the truck was floored and it showed the RPMs at like 3600 or what ever it was. But any real life input would be appreciated.

[gmckenzie]

lly-zf6 wrote:

gmckenzie wrote:

lly-zf6 wrote:
I just picked one up about 2 weeks ago. Double Cab loaded up LT.

While I do wish it had an 8 or 10 speed, the 6 doesn't seem to do a bad job. And historically the 6L90 has been a pretty reliable tranny.

I have only towed with it 1 time. My fiver is about 9600lbs ready to camp. It did a good job by my expectations. It's not a diesel, which have had in the past, and didn't want to go that route. RPM's towing run from 2k up to pushing 4k in the hills. This is expected with a normally aspirated V8. Got about 9mpg according to the meter. Power was good at that weight. I don't think I'd want to tow the 17k it is rated for though.

Under normal driving it's showing about 15mpg. I haven't checked it since I'm still one the first tank. I don't expect it to get much better.

Curious. What would you think is a max weight that you'd be comfortable with? Would say 14K be more than you think it could handle?

My guess is it would be fine at 14k as long as you don't live in the Rockies. It's pretty hilly in our area of western PA and it seemed to have no issues at all towing 10k. Just have to tune out the high rpm's on the big pulls. I pulled 1 hill that's about 8% for a little over a mile. Held 60 mpd @ 3600 with out loosing any speed.

LOL. Central BC here so yeah, might be an issue 🙂

[lly-zf6]

gmckenzie wrote:

lly-zf6 wrote:
I just picked one up about 2 weeks ago. Double Cab loaded up LT.

While I do wish it had an 8 or 10 speed, the 6 doesn't seem to do a bad job. And historically the 6L90 has been a pretty reliable tranny.

I have only towed with it 1 time. My fiver is about 9600lbs ready to camp. It did a good job by my expectations. It's not a diesel, which have had in the past, and didn't want to go that route. RPM's towing run from 2k up to pushing 4k in the hills. This is expected with a normally aspirated V8. Got about 9mpg according to the meter. Power was good at that weight. I don't think I'd want to tow the 17k it is rated for though.

Under normal driving it's showing about 15mpg. I haven't checked it since I'm still one the first tank. I don't expect it to get much better.

Curious. What would you think is a max weight that you'd be comfortable with? Would say 14K be more than you think it could handle?

My guess is it would be fine at 14k as long as you don't live in the Rockies. It's pretty hilly in our area of western PA and it seemed to have no issues at all towing 10k. Just have to tune out the high rpm's on the big pulls. I pulled 1 hill that's about 8% for a little over a mile. Held 60 mpd @ 3600 with out loosing any speed.

[Sjm9911]

And ita not awful of gas for driving, it got better mpg ( by like 1 or 2 ) then my 1500. The problem is i do go faster, way faster. Maybe covid, no one on the road, or the truck. But i can easily look down at the speedo and see im doing 90.

[gmckenzie]

lly-zf6 wrote:
I just picked one up about 2 weeks ago. Double Cab loaded up LT.

While I do wish it had an 8 or 10 speed, the 6 doesn't seem to do a bad job. And historically the 6L90 has been a pretty reliable tranny.

I have only towed with it 1 time. My fiver is about 9600lbs ready to camp. It did a good job by my expectations. It's not a diesel, which have had in the past, and didn't want to go that route. RPM's towing run from 2k up to pushing 4k in the hills. This is expected with a normally aspirated V8. Got about 9mpg according to the meter. Power was good at that weight. I don't think I'd want to tow the 17k it is rated for though.

Under normal driving it's showing about 15mpg. I haven't checked it since I'm still one the first tank. I don't expect it to get much better.

Curious. What would you think is a max weight that you'd be comfortable with? Would say 14K be more than you think it could handle?

[Sjm9911]

I like mine, i would have liked the 10 speed trans better but the 6 speed is not as bad as i thought it would be. My TT is light though. For me its a world of difference from my 2012 1500 GMC sierra. Gas millage is a bit better, truck is bigger , mirrors and back up camra to hook up the TT are good. Seats not as conformable. But ok for a longer drive. The power is very noticable. I can pass trucks , cars at will now. Before i was at everyone elses will, lol. Its a nice truck, and i didnt want or need the diesel. I think i got a decent dwal during the covid, before people were looking at buying stuff. So for me it was a win. Tow mirrors are excellent, more cab room for bigger people, this can be a negative if you are short. Bigger bed, so you can take more stuff with you. Ask away, i will try to answer best i can. I had it on 5 trips so far this year. All about 3 to 6 hours away. Oh, giant fuel tank. So the same if not a little better on mpg but the tank makes for half the fuel stops. Wish i had that last year , i did nj to disney world.

[kellem]

No question, I really like the looks of the Silverado and the 6.6 has impressive numbers but unfortunately I need a truck prompto so felt Ford pulled ahead with the 7.3 10spd auto especially for my needs, a designated tow vehicle.

I've owned 5 Chevy trucks and been very pleased and see quite a few 2020's locally including 2 retired friends of mine who really like their 6.6 trucks.

GM needs to catch up in the tranny department.

[lly-zf6]

I just picked one up about 2 weeks ago. Double Cab loaded up LT.

While I do wish it had an 8 or 10 speed, the 6 doesn't seem to do a bad job. And historically the 6L90 has been a pretty reliable tranny.

I have only towed with it 1 time. My fiver is about 9600lbs ready to camp. It did a good job by my expectations. It's not a diesel, which have had in the past, and didn't want to go that route. RPM's towing run from 2k up to pushing 4k in the hills. This is expected with a normally aspirated V8. Got about 9mpg according to the meter. Power was good at that weight. I don't think I'd want to tow the 17k it is rated for though.

Under normal driving it's showing about 15mpg. I haven't checked it since I'm still one the first tank. I don't expect it to get much better.

[gmckenzie]

I don't have one, but have been looking at them.

I would not expect a 10 speed until 2022 at the earliest. This is my biggest disappointment and one reason I may end up with Ford and the 7.3L.

I know the GM factories had a strike early in the year and then Covid hit, so dealerships where I am don't even have the **** things to look at or test. And they have stopped taking 2020 orders and are not taking 2021 orders yet. Applies to both Ford and GM.

[Grit_dog]

Not experience but opinion.
I wouldn’t spend $5 on the last place engine for power combined with the oldest transmission.
That is unless I wasn’t planning on really towing anywhere near it’s capacity.
GM gasser trucks are like Ram diesels. Once they get with the program transmission wise, they’ll be viable imo.