6.6 gas

brendon444 · February 13, 2019

Why the 10 speed hate??

Seems to make sense. Can have a 3.23/3.42 rear end with 3 overdrive gear for running empty with increased fuel mileage.

But have a lower overall gear range, better than what 4.10’s can offer with a 6 speed. Effectively could be equal to 4.56 6 speed.

10L90 tows great and drives great. Stays in the power with out the huge drop when shifting. Linear power output. Change isn’t bad guys.

SierraHD17 · February 13, 2019

One reason... running a 7000+ pound brick down the highway at 1300 rpm where it makes absolutely zero power will not be conducive to fuel economy. How about 3.73 or 4.10 with a 10 speed... 4.10 with the GM 10 speed would be only a little deeper than a 4.56 geared 6 speed truck... in first gear only. Would be a nice combination from factory however although I really don't see a need for 10 speeds in any application when 3 of them are wasted as overdrives. Even 3.73 with the 10 speed would be okay. Move forward... stop trying to always be the same all the time.

Edited February 13, 2019 by SierraHD17

avalonandl · February 13, 2019

On 2/12/2019 at 12:47 PM, Jollygreengiant said:

It could. I'd also say that if he can drive in a way that gets 16.0 out of a 6.0 he should be getting 18+ out of the 6.4.

18 mpg out of a gas 3/4 that weighs 7500 lbs. mmmm don't think so. I really don't believe the Hemi 6.4 is that much more efficient. So we agree to disagree.. Cheers

Big Whiskey · February 14, 2019

On 2/11/2019 at 1:16 PM, SierraHD17 said:

You will not get the fuel economy or the performance of the half ton 6.2 truck. If that's your big go to then stick with the half ton truck. This new 6.6 will be right in the same neighborhood as the current 6 liter for economy with a little better torque curve. The weight of the trucks alone negates the economy portion of the equation combined with an ever increasing height of stance and the aerodynamics up front of a brick. Not to mention the same 6 speed trans and a slightly more efficient direct injected engine with its efficiency increase offset by the increase in displacement.

Performance wise it's an 87 octane tuned 400...... well drive a 5.3 half ton on 87 and then drive a 5.3 even on E85... world of difference in power and goes from a sack to not. Expect this 6.6 to be a sack lol. I know you will say something along the lines of "I hope you are wrong" but I won't be. It's just how the cookie crumbles.

I really hope you're wrong...but this is probably the most accurate description of how the new 6.6 is going to feel...especially with 3.73's I'm sure it'll be neutered with all kinds of torque management, and the extra compression won't really matter because it'll be tuned for 87 octane. And, it'll probably still get 12-13 mpg, haha.

On 2/11/2019 at 1:47 PM, ApertureX said:

Just out of curiosity (and trying to obtain knowledge):

If anyone has had a 2500HD or 3500HD with the 6.0 gas engine, did you ever measure your MPG?

If so, could you post what you got for your City, Highway, and/or Combined MPG?

As someone else said, there's a bunch of posts about this, but I'll save you some time. With anything, you'll always have guys that claim to get crazy results that people can't believe....but the averages for a 6.0 2500HD are something like this:

Driving empty like there's an egg between your foot and the gas pedal: 14-15 mpg avg

Driving empty like you're not paying for your own gas, and you have to poop: 10-11 mpg avg

Driving like a normal person, with a mix of city & highway: 12-13 mpg avg

Towing anything over 5k pounds: 6-9 mpg avg, depending on speed and aerodynamics of what's being towed

On 2/11/2019 at 8:05 PM, Chevyguy85 said:

Hey don't forget the 6.6 gasser is going to be soooooooooo much more fuel efficient with the 4.10 going bye bye and only the 3.73 rear end lol :-D

Yep, that's right! Guys are going to be trading their commuter cars for new gasser HD's because of the super duper efficiency of the new 3.73's!

SierraHD17 · February 14, 2019

Yeah my 2017 HD was soooooooo efficient with its 3.73 gears over 4.10.. That big bad 15 mpg it got stock was so much more impressive than the 14 to 15 I can still get with the 4.56s and slightly larger tire.... wait a minute lol.

And yeah.. its 400 cubes so it will have more torque but be held back by extremely conservative 87 octane tuning like the every other gas HD they have ever built. Probably get 40 hp and 40 to 50 ft lbs out of good fuel and ignition timing alone if you hook it to an ecm you can tune. The stock tuning is set up for the guy at max gcwr with foot to the wood full of cheap 87 going up the side of a mountain.

Edited February 14, 2019 by SierraHD17

dieselfan1 · February 14, 2019

I kind have to chuckle about all the MPG bashing.

If you can afford to pay for the truck you can afford the gas. Gas is cheap right now too. If you want better MPG get a diesel.

swathdiver · February 14, 2019

3 hours ago, SierraHD17 said:

The stock tuning is set up for the guy at max gcwr with foot to the wood full of cheap 87 going up the side of a mountain.

Or crossing Death Valley in the summer at GCWR.

2016HD · February 15, 2019

The stock tuning is set up for the guy at max gcwr with foot to the wood full of cheap 87 going up the side of a mountain.

Edited 6 hours ago by SierraHD17

Um Yep That is what these trucks are designed to do!! Not be hotrods like the 1500's.

Yes they are decapitated a bit from the factory. However would you like to be GM and have to pay for extensive warranty issues if they were tuned to run at max Hp without a consideration for breakage?

I hope the new 6.6 is as strong and reliable as the l96. However put the 4.11 back!

SierraHD17 · February 15, 2019

52 minutes ago, 2016HD said:

The stock tuning is set up for the guy at max gcwr with foot to the wood full of cheap 87 going up the side of a mountain.

Edited 6 hours ago by SierraHD17

Um Yep That is what these trucks are designed to do!! Not be hotrods like the 1500's.

Yes they are decapitated a bit from the factory. However would you like to be GM and have to pay for extensive warranty issues if they were tuned to run at max Hp without a consideration for breakage?

I hope the new 6.6 is as strong and reliable as the l96. However put the 4.11 back!

I run my trucks exceptionally hard with far more aggressive tuning and get hundreds of thousands of miles. GM's oem tuning is trash.. hence why there is such a huge aftermarket catering specifically to how bad it is. The way they set up their transmissions is more conducive to warranty work than what I do. And at least I don't drive around in a slug that struggles to get out of it's own way.

Edited February 15, 2019 by SierraHD17

C/K Man · February 15, 2019

Do we know that 4:11's will not be available in the 2020's? When I bought my 2012 3500, seemed that all the 6.0L trucks on the lots were 2500's with 3.73's. I had no trouble ordering a 6.0L 3500 with 4:11's, and it pulls fine. Gas mileage is what you would expect, but I didn't buy it for fuel economy.

Chevyguy85 · February 15, 2019

5 minutes ago, C/K Man said:

Do we know that 4:11's will not be available in the 2020's? When I bought my 2012 3500, seemed that all the 6.0L trucks on the lots were 2500's with 3.73's. I had no trouble ordering a 6.0L 3500 with 4:11's, and it pulls fine. Gas mileage is what you would expect, but I didn't buy it for fuel economy.

All the info released thus far has only shown 3.73s and no mention of 4.10 other than to have ---- or N/A in that area.

2016HD · February 15, 2019

34 minutes ago, SierraHD17 said:

I run my trucks exceptionally hard with far more aggressive tuning and get hundreds of thousands of miles. GM's oem tuning is trash.. hence why there is such a huge aftermarket catering specifically to how bad it is. The way they set up their transmissions is more conducive to warranty work than what I do. And at least I don't drive around in a slug that struggles to get out of it's own way.

Did i say that there tuning was perfect? No. Does there trans tuning and engine tuning need some tweaking? Yep. However i keep hearing you say that these ecms are not tunable? Hmm Not much aftermarket support? Well if you know how to tune? There is actually a lot of potential yes.

However as you stated These trucks are designed to do WOT up Steep hills while fully loaded? How much of that do your trucks see while in Alberta? Ive tuned many 6.0l for better mpg and HP along with a much improved trans life but if you dont watch the timing and knock while towing and setting the tune. You will have issues. However if you wish to keep your warranty intact?? Your kinda stuck with the stock tuning for a few years.

The New 6.6 with 3.73 gears is not going to be much better overall than the current truck with the l96. But it is an improvement.

What i dont understand is why what seem to be loyal GM fans continue to bash there own equipment?? Every brand needs tweaking!! however what brand has the least amount of trans and engine problems??

SierraHD17 · February 15, 2019

2 hours ago, 2016HD said:

Did i say that there tuning was perfect? No. Does there trans tuning and engine tuning need some tweaking? Yep. However i keep hearing you say that these ecms are not tunable? Hmm Not much aftermarket support? Well if you know how to tune? There is actually a lot of potential yes.

However as you stated These trucks are designed to do WOT up Steep hills while fully loaded? How much of that do your trucks see while in Alberta? Ive tuned many 6.0l for better mpg and HP along with a much improved trans life but if you dont watch the timing and knock while towing and setting the tune. You will have issues. However if you wish to keep your warranty intact?? Your kinda stuck with the stock tuning for a few years.

The New 6.6 with 3.73 gears is not going to be much better overall than the current truck with the l96. But it is an improvement.

What i dont understand is why what seem to be loyal GM fans continue to bash there own equipment?? Every brand needs tweaking!! however what brand has the least amount of trans and engine problems??

The new ones aren't and might get support and might not. Why is warranty even part of the discussion? I mean it's irrelevant to what I am speaking of. Most people have figured out if you like gm maybe paying you leave it stock. End of warranty talk.

I'm not loyal to GM either lol... they just have good aftermarket support making them able to be modded.. well sorta. Missed the boat on that one with the E78 but live and learn.

Plenty of steep hills in Alberta... try highway 43, 28, 93 etc with a load. They don't have to be 15 miles long but they are there. My goal is to not be at wide open throttle all the time whereas stock that's where it wanted to be. And voila now it's not.

Nobody is perfect but GM could learn a few things on the tuning side... would hurt a lot of tuning business if they did.

The 6.6 will have plenty of support and tune capabilities... just need an e92 controlling it in something other than its original application.

If I wanted just a stock truck and do nothing to it I would run a Super Duty with a 6.2 and 4.30s.

My 2017 2500Hd is about as stock as I will run in a truck being tune, muffler, 4.56 gears and a Detroit locker. If the ecm was better supported it would have a cam and headers I bought for it but it's not. Oh well.

Edited February 15, 2019 by SierraHD17

Cowpie · March 14, 2019

Well, the 6.0 Vortex is far from dead. Both Isuzu and Fuso are bringing out new Class 5 trucks with the 6.0 Vortex and Allison 1000 transmissions. Isuzu will have two new models, one with a GVWR of over 19,000 lb. Some things just stand the test of time. My 2015 2500 6.0 will be with me for a long time to come. Just like my 30.06, 30-30, and 45-70 rifles. Some things just get the job done and do it well.

https://www.ccjdigital.com/isuzu-announces-plans-for-two-class-5-gas-trucks-updates-to-n-series-and-f-series/?utm_source=weekly-equipment&utm_medium=email&utm_content=03-12-2019&utm_campaign=Commercial Carrier Journal&ust_id=480221824f761d3e1f8cedd4a1049565&utm_term=newsletter-2-weekly-equipment-position-2

https://www.ccjdigital.com/fuso-debuts-industry-first-class-5-gas-cabover/?utm_source=weekly-equipment&utm_medium=email&utm_content=03-12-2019&utm_campaign=Commercial Carrier Journal&ust_id=480221824f761d3e1f8cedd4a1049565&utm_term=newsletter-2-weekly-equipment-position-5

Edited March 14, 2019 by Cowpie

Gagliano7 · March 14, 2019

On 2/13/2019 at 11:59 AM, SierraHD17 said:

One reason... running a 7000+ pound brick down the highway at 1300 rpm where it makes absolutely zero power will not be conducive to fuel economy. How about 3.73 or 4.10 with a 10 speed... 4.10 with the GM 10 speed would be only a little deeper than a 4.56 geared 6 speed truck... in first gear only. Would be a nice combination from factory however although I really don't see a need for 10 speeds in any application when 3 of them are wasted as overdrives. Even 3.73 with the 10 speed would be okay. Move forward... stop trying to always be the same all the time.

My buddy just bought a 2019 f150 4x4 5.0 10 speed with 3:73 gears and that thing rips. The 10 speed works great with the 3:73 gears even so many on here say they don't need those gears with a 10 speed. If 4:10's were a choice he would have went that route. So far he is averaging 19 mpg.