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6.6L gas, will it disappoint??

kylant

By kylant
in 6.6L Gas V8 (L8T)

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Another JR Senior Enthusiast

Another JR

Posted
Posted
21 minutes ago, the8rotor said:

Identical experience with me between a 2021 and my 2024 L8T. Zero oil consumption 

Same here for my 2021. 

  • Like 1
Doodle Enthusiast

Doodle

Posted
Posted
On 9/22/2023 at 8:53 AM, Moldman said:

 It's all in what your expectations are. I have had both and currently have a '20 6.6 gas. The last diesel I had was a '15. The damn thing lived in the shop. I couldn't take it anymore and went gas.

 I pull a 12k fifth wheel and it actually surprises me how well it does. We made a 1500 mile run this summer to Tn. from Pa. The truck pulled ever hill at 65-70 and averaged 8.9mpg. Does it pull with ease like the Duramax, not even close. But gets the job done fine and at 40k miles has never missed a beat.

 I have a 24 on order and figure it can only be better with the 10 speed.

I have had the same experience.  Have a 2015 diesel, had a 23 6.6 gas, and now a 24 6.6 gas.  Towing 6000 lbs is nothing for the gas.  I live in western KS where it is flat, but I have no issues pulling 12-14K with the gas.  Once you start getting up to 16-18K a diesel will be better.  The 6.6 gas can do it, but it will rev a lot and gas mileage will be 6-7 at best.  My 24 gas actually has a higher GCVWR than my 15 diesel.  That is primarily due to the frame and brakes, but the diesel will definately pull heavy loads much easier, but it does show the gas is more than capable.    

 

I can speak to experience on the 6 vs 10 speed.  They are both great transmissions.  The 6 speed was more than capable.  They 10 speed just keeps the 6.6 in a better powerband when towing.  I actually thing the 6 speed was quicker unloaded than the 10 speed but towing wise the 10 speed is better in my opinion. 

 

The 6.6 gas has been out since 2020.  So far they have proven to be very reliable, much like the 6.0 gas.  Not saying the L5P isn't reliable, but if you do have issues it's gonna take big dollars out of warranty plus the $10K upfront cost. 

 

Mileage wise I get 12.7 with the gas and my 15 LML I'm 14.5-14.7 average.  With our local fuel prices that's a wash plus I don't have to use DEF or additives with the gas.  If I towed heavy all the time I would get the diesel as the economics would work out better for fuel mileage.  I might tow 5K a year.  Not worth it for me to have two diesels.  

 

The newer diesels are monsters for power.  If you like or need that you will not like the 6.6 gas.  If you just need something reliable with cheaper upfront cost that will still get the job done I'd go for the 6.6 gas.  I have said many times I wish GM would come out with like a 7.0 with 450 hp/500tq and that would start to close the gap a bit between gas and diesel.  Maybe with some tuning that's already attainable with the 6.6.  

Jettech1 Senior Enthusiast

Jettech1

Posted
Posted (edited)
On 9/22/2023 at 8:21 AM, kylant said:

Looking at moving from my '22 Duramax into a '24 gas AT4.

concerned that i may regret giving up diesel, simply for the power. 

sounds like these new 6.6/10 speed combos are pretty darn good

 

I rarely tow. when I do, it is my 6000lb boat or a dump trailer from the gravel yard. 

 

I briefly had a 7.3 gas ford, and was not very happy with it. mostly because of the gearing and the tranny didn't know what the hell it was doing.

 

 

reasons for going back to gas are the simplicity of them, lower down time risk, cheaper fuel.

 

anyone have any insight or thoughts on gas vs diesel, power, regrets, etc...

thanks

 

 

Last year around May of 22 I was looking for an HD truck.  I did a ton of research on both the gas and the diesel.  So I started calling the "country" dealers way away from Atlanta because they weren't marking them up 10k above MSRP like my local Atlanta dealers were.  Anyhow every dealer I talked with said don't buy the diesel unless you are using it for hot shotting or towing above 15k.  And of course I asked why and they all said the new diesels are ridden with emission problems and people are trading in their diesels for the gasser models.  So after doing more research I found that bit of information to be true.  In the end I bought a 22 gasser and am in total love with it.  A little over 1 year and 16k miles, it's been the best vehicle I've ever owned in my 57 years of life.  42 of those years driving...lol... It's the vehicle I've always wanted and that's the one I can't wait to drive everyday and tow our camper with.  It's nothing shy of amazing!!  Oh and I just have the Custom model with several options on it, it's not like I own a Denali gasser.  Basic but true!

Edited by Jettech1
lurker_007 Enthusiast

lurker_007

Posted
Posted

I have owned both gas and diesel 2020+ HD trucks.  I currently own a 2024 gas 3500 that I traded a 2023 3500 diesel for and have a gas ZR2 on order that will hopefully be here soon.  I use my truck as a daily driver but also pull my 12,000lb 5th wheel around 10,000 miles a year.

 

   I’ve pulled it with both gas and diesel all over the eastern United States from the flatlands southeastern us to the mountains of Virginia and WV.    The gas is more than enough for 99% of HD truck buyers.   No def, no emissions related issues, cheaper fuel.  Also me personally, I average about 14.5-16 mpg unloaded with my gas on my daily commute. I averaged 15ish with the diesel.  Towing I average 8.5-9.5 with the gas and averaged 9.5-10.5 with the diesel.   So no real MPG benefit for me.  Also save about $11,000 upfront compared to the diesel.
 For me it’s a nobrainer but if you’re pulling 15,000lbs plus on a daily basis, sure get the diesel.  If you live out west and climb 8000-10,000 ft regularly?  Get the diesel.   But as for me, GAS all day.  
 

The diesel certainly has its place, I’m just honest enough with myself to know that I don’t need it. 
 

You will get the occasional person that says “hey nice truck.” And then followed by “Oh man, you don’t have the diesel!”    
At the end of the day, your money, your choice.   I for one, don’t care to get other dudes rocked up at the red light over the chitter chatter of my duramax.  
 

  • Like 1
lsttype Enthusiast

lsttype

Posted
Posted

Just picked up my 2024 gmc and I love it! Seamless shifting, good trans temps (145), great new interior and it sits up higher than the Ford. I ordered it 2wd and it sits like a 4wd. Very happy I ditched the 7.3 Ford!

  • Like 2
Flatus Enthusiast

Flatus

Posted
Posted

Awesome looking truck. Mine is also a 2wd and I like how they still look like a 4wd.

  • Like 1
UWSkier Enthusiast

UWSkier

Posted
Posted
6 hours ago, lsttype said:

Just picked up my 2024 gmc and I love it! Seamless shifting, good trans temps (145), great new interior and it sits up higher than the Ford. I ordered it 2wd and it sits like a 4wd. Very happy I ditched the 7.3 Ford!

You'll really like it after 5-6000 miles.  Brakes improve, shifting improves, power improves, fuel economy improves.  I love mine!

  • Like 1
Jettech1 Senior Enthusiast

Jettech1

Posted
Posted
14 hours ago, UWSkier said:

You'll really like it after 5-6000 miles.  Brakes improve, shifting improves, power improves, fuel economy improves.  I love mine!

That's some great advice for everyone that buys one of these HD trucks.  My 22 started coming into its own around the 2500 mile mark but kept getting better and better as the miles added up.  Just from monitoring my catch can I could tell the engine was seating in nicely right around the 10k mark.  Now at 16k miles I hardly get any oil in it between my 5k mile oil changes.  Prior to 10k I was getting a little over an ounce every 1k miles.  Now maybe 1/2 ounce at the most every 5k.  So it took it a while to finally seat in but never used any oil from day 1 so I wasn't worried about it.  Good stuff sir!!

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