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Good Evening Folks,

I had posted in here earlier about the "fudge factor" if any in a GVWR for a 1500. Thank you all for the feedback. As much as I'd like to do the smart thing financially and just keep what I have, pay it off in a few months and enjoy having no truck payment...........after reading a lot of the posts and/or having the "itch" for something new, I am doing a little fact finding right now.

Today I test drove two Sierra 2500s. One was a Duramax AT4 crew cab and the other was the new 6.6 L gas engine SLT level. Both were very, very nice rides with lots of bells and whistles on the truck. And both would probably be over kill for my smaller trailer and/or how often I truly wind up towing things. However, when I priced out a 1500 with a max trailering package with the options I'd want on it.......it was almost as much as the gas 2500. To be honest, I probably would be fine with the 1500 max package given my towing concerns mentioned in the previous post.

However, my question to y'all is what if any feedback do folks have on this new gas 6.6 L V8 that is replacing the tried and true 6.0 L V8 engine that Chevy/GMC had for years in their 2500s? Pros/Cons? Any maintenance concerns? Towing capability concerns? Gas mileage concerns?

I surely do not have anything in my driveway to justify the nearly 10K more initial costs and long term maintenance costs of a diesel even though they are a blast to drive.

I will say that this new 6.6 seems to have a heck of a lot more get up and go than the 6.0 V8 of old. To me those 2500s I had tested with the 6.0 seemed to be sluggish, especially when compared to the Duramax 2500s. But this new gas engine seems to be close to the diesel in terms of the "butt dyno." And for my limited towing requirements in both weight and actual use, the gas HD truck would suit my needs just fine.

My only real hesitation other than if I am going to make a move on an HD truck instead of keeping my 1500 is that I have always been warned to stay away from first year engine or transmission changes to allow for recalls, problems, etc....etc.... to be worked out down the road.

Thank you all for any input you can provide.

Respectfully,
Jim
 

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In my opinion it's still too early to tell. Seems to be liked over the 6.0 as far as power goes on all accounts I've read. Fuel milage also seems to be better than the 6.0.

It will probably turn out to be a good motor. No DFM so it's already got that going for it lol.

Will never be able to touch the diesels though as far as power goes. Especially when your towing. But it's also substantially cheaper.

As biased as they are sometimes, the fast lane truck has some decent videos out on the 6.6 gas. When I bought my 15 they had a few of them on the lot. Most were diesels but they had a few with the gas motor. Didnt bother looking at them because I wasnt at all interested in a gas 2500. But I kinda wish I drove one just to see how it is lol.
 

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I keep checking this post for more replies, surprised there are not. I'm very interested in this as my next truck will likely be 2500 gasser. Currently in 1500 SLT NHT with 6.2l. Wanting to see what mpg comes out at, I average about 17 now.
 

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If I ever need another 2500 I'll probably consider the gas job. I wish they would have stuck with the 4.10 instead of going back to the 3.73. GM can be frustrating as hell sometimes. I'm really enjoying my 6.2 right now though, even more than the diesels I've had, I'd have to have a good reason to go away from it.
 

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I am super-curious how the 6.6 ends up- a modern 400 ci gas V8. Not many of those coming online these days,
5th gen LS, pushrod, iron block (big plus), direct injection, no AFM.

 

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I am also interested in this new beast. From the reviews I had seen it was rated or reviewed well. I do agree as stated I am also a little wary about 1st year production bugs to be worked out.
 

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I've been eye balling the new 2500s as well, but will be waiting a bit before I take the plunge.

I've watched some fast lane truck videos too, and the new gasser was almost 2 minutes slower on the gauntlet, than a 2017 6.0 gasser they tested. But the new truck was towing about 3000lbs more. Can't help but think 4.10 gears would probably do away with that 2 minutes.

Give it some time, and we'll be hearing about the 6.6 gasser, I'm sure. Hopefully it turns out to be as dependable as the 6.0
 

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MMZ71 said:
I've been eye balling the new 2500s as well, but will be waiting a bit before I take the plunge.

I've watched some fast lane truck videos too, and the new gasser was almost 2 minutes slower on the gauntlet, than a 2017 6.0 gasser they tested. But the new truck was towing about 3000lbs more. Can't help but think 4.10 gears would probably do away with that 2 minutes.

Give it some time, and we'll be hearing about the 6.6 gasser, I'm sure. Hopefully it turns out to be as dependable as the 6.0
That test isn't really anything to go by considering they don't manually shift like 95% of the people who tow

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^^^^ this. All they had to do was keep it in (maybe?) M3 and they would have gotten much better time. That's what that button is for.
 

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But then the test wouldn't be the same. I know they don't use the best real world method, but for consistency, and comparing apples to apples, I can't think of a better way.

As soon as you start manually shifting, or modulating the throttle, you've added another variable, that is not neccessarily precisely repeatable.
 

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MMZ71 said:
But then the test wouldn't be the same. I know they don't use the best real world method, but for consistency, and comparing apples to apples, I can't think of a better way.

As soon as you start manually shifting, or modulating the throttle, you've added another variable, that is not neccessarily precisely repeatable.
I agree, I just wouldn't base your buying decision on that test

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No doubt. Those tests alone are more entertainment value than science.

I've been looking at Custom trim 2500s, in Red Hot, of course, and they only come with the gas 6.6.. The only things I'd like to be able to add, are the missing buttons on the steering wheel, audio, and DIC controls, along with the dual climate HVAC. Even building one on the Chevy site you can't add those two. So the only way I see to get one configured like I want is, get a LT, then buy paintable bumpers, and grille bar. Really like the red/black exterior on the Custom.

I could probably live without the steering wheel buttons, but with a wife that has hot flashes, and me being cold natured, the HVAC are always on very different settings.
 

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I have about 300 miles on mine so far. Still going easy on it. I will be pulling my trailer in about two weeks. I will be sure to post up after.

I will say that the 28" fan up front is really loud when it gets going. I mean ...really loud... Cant hear it with windows up... But with windows down, its all you hear. Sounds like those big warehouse fans.

One other note. Mine came with bad alignment from the factory. I took it back to get alignment already. They said the toe was off. It is still not right. I am taking it back this week. Its a bit frustrating, but not the end of the world.

All in all, I am very happy with it so far.
 

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Cool, thanks for that real-world input.
Re: Fan- It just depends on the fan. Older Jeep Wranglers and Cherokees with the 4.0L inline-6 are REALLY loud when the fan clutch kicks-in. Sounds like an old school bus.

The wife and I were looking at the 6.6L for her new horse-puller (Duramax is just too much maintenance expense and stuff to break), we opted for a leftover-new 2019 2500HD crew cab with the 6.0L. There was only really reg cab long bed 2500/3500s with the 6.6L at Connecticut dealers at the time a few weeks ago for some reason.
 

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Yea, around here the gasser is hard to find. Almost every dealer in the area had a duramax. There was one dealer that had a gasser ltz... but, I just couldn't swallow the cost.

I found this gasser and jumped on it. It had only been on the lot for a few days. After the sale, the salesman said he was getting calls from all over the midwest from dealers trying to transfer it as the gasser LT is tough to find. I think I got lucky.
 

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Yeah, looks like GM started out with mostly LTZ trims and up. Even looking online, you don't see many LTs. Also, there isn't a red Custom double cab within 400 miles of me right now.
 

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Seems to be the same with the diesels. When I bought my truck, all the dealer has was LTZ and High Country trims in the 2020 HD trucks.

And even still that's the vast majority of what they have. And they must sell like crazy because they are always getting new inventory in. I keep tabs on what they have in stock just for fun lol.
 

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I just did a 500 mile round trip while pulling a 6,000lb trailer. The trip included a combo of flat interstate and very hilly terrain (1 - 2 % grades). The 6.6 gasser handled it all great. Trailer mode was amazing.

I had to keep reminding myself that the trailer was back there so as to drive safely... Other than braking...couldn't tell it was there. My average for the whole trip was 9.6mpg.

Shifting in tow/haul mode with cruise was spot on. It never dropped more than about 3-4 mph before downshifting. Downhill did great. The engine/tran did a great job of maintaining speed. We did some site-seeing without the trailer and some pretty steep grades... I went to manual and let the engine do all the braking. It did great.

Very quite in the cabin. We could talk without raising our voices.

Very happy with the engine and the truck in general.
 

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Nice. I commend GM's bringing-on of another big block gas engine as opposed to trying to boost a V6 to get close to what an average V8 can do. Given the new 6.6 L8T is rooted in LS architecture, I'm pretty sure it will be another reliable, long-lived engine.

Weird they would label this a "small block" considering this 6.6 and the previous 6.0 make more than 50% more power than the infamous 7.4L 454.

Gory details:
https://gmauthority.com/blog/gm/gm-engines/l8t/

GM RPO Code: L8T
Type: 6.6L V-8 gasoline
Bore & Stroke (in / mm): 4.06 x 3.86 / 103.25 x 98
Block Material: Cast iron with nodular iron main caps
Cylinder Head Material: Cast aluminum
Compression Ratio: 10.8:1
Valvetrain: Overhead-valve, two valves per cylinder, variable valve timing
Fuel Delivery: Direct fuel injection
Recommend Fuel: 87 octane
Power (hp / kW @ rpm): 401 / 299 @ 5200 (SAE certified)
Torque (lb.-ft. / Nm @ rpm): 464 / 629 @ 4000 (SAE certified)
Predecessor: 6.0L V8 L96/LC8
 

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I did finally upgrade to 2500 but went Duramax. I drove a couple gas 6.6 and thought they were great...then tried a diesel and it was over. Seriously though, the gas was fantastic engine.
 
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