6.6 GM. Gas

Sjm9911 wrote:
16 hyway not towing, at speeds of 75 to 80. 11 towing a 6k trailor at 65-70. 12 around town.

That seems pretty optimistic.

^Yeah it will make GM at least competitive in the HD gasser market.

Now if GM actually dug a little deeper into their large bag of LS engine parts and assembled something (easily) that would one up the Godzilla, I think they’d be money ahead.
Or maybe their plan works and a large % of folks who buy these upgrade to a diesel, in short order, thus effectively selling 2 trucks per owner to that group.
In that case it’s good marketing.
Also have to account for how many hd gassers are private owner sales vs the very large market for govt or company trucks where the ultimate HP game is not played as much.
Given the runaway popularity with diesels in HDs, I could believe that the private owner market is smaller than the public entity/corporate market.

I am really happy to see they are switching over to the 10 speed with the 6.6 gas. I think that will make a big difference in towing. That should have been done when they released the engine in the first place, in my opinion.

Sandia Man wrote:
We have both the 6.0 and 8.1 versions and of course they are thirsty when towing, heck they are thirsty when not towing. I would imagine the new 6.6 would be more fuel efficient than prior models mentioned above, but more than likely it still would not be as good as diesel mpg. We don't fret the decline in mpg with our gas engines since they are specifically used for RVing, they are not daily drivers and otherwise sit around waiting to be called to duty.

Best thing is we never had any issues with these engines, in fact they have never been back to a dealer, just followed periodic maintenance for lubrication, most of which I do myself. The 6.0 is used to tow our our nearly 11K# toyhauler, our 8.1 is used in our nearly 40', W24 chassis, 30K# Class A with toad. We live at 6K' and do most of our RVing in the four corner states at high elevation, our gassers have handled many of the severe inclines without issue.

Both of those engines are solid as an anvil! Pretty tough to beat the LS engines. :C

Just curious, I see you have a newer Duramax. Why trade in already? I have the same truck and love pulling with it.

Dan

I had the 6.6 gas in a reg cab dually. I towed over 15k gooseneck trailer with hay. No issues. I towed my 9500lb travel trailer with no issues.

Moving from a 2019 Dmax, it will not be the same.

16 hyway not towing, at speeds of 75 to 80. 11 towing a 6k trailor at 65-70. 12 around town.

Pro's: Direct injection allow for higher compression which improves power and fuel economy

Con's: Direct injection tends to produce carbon on the back side of intake valves. Questionable long term effects.

We have both the 6.0 and 8.1 versions and of course they are thirsty when towing, heck they are thirsty when not towing. I would imagine the new 6.6 would be more fuel efficient than prior models mentioned above, but more than likely it still would not be as good as diesel mpg. We don't fret the decline in mpg with our gas engines since they are specifically used for RVing, they are not daily drivers and otherwise sit around waiting to be called to duty.

Best thing is we never had any issues with these engines, in fact they have never been back to a dealer, just followed periodic maintenance for lubrication, most of which I do myself. The 6.0 is used to tow our our nearly 11K# toyhauler, our 8.1 is used in our nearly 40', W24 chassis, 30K# Class A with toad. We live at 6K' and do most of our RVing in the four corner states at high elevation, our gassers have handled many of the severe inclines without issue.

Great engine mated to a good-in-2022 transmission. Both are dead reliable. I wish GM used the 10spd. Budget for 8mpg and you may be happy with 9-10mpg.