Jump to content

6.6 Gas MPG

brendon444
 Share

Recommended Posts

SkidooSteve12 Enthusiast

SkidooSteve12

Posted
Posted

Seeing my truck in the parking lot next to other pickup trucks, I can see why the gas mileage isn't much better because it is so much taller and has a big front end that is pushing a lot of air and taking in a lot of air through the grill. And the stock tires on 20" wheels are huge compared to what we used to run on 2500HD trucks, so that eats up some MPG's and I think that's why some people are getting better MPG's than others. Here is a comparison between sizes and at the bottom what is available for the 2020 HD.

 

455262954_Tiresizes.jpg.884733604db0d0d495de8fdf7b44f0f3.jpg

 

 

 

Does anyone else use the aCar or Fuelly app? I have since I bought my truck and here are some screen shots of my info so far. I have noticed that the 2 highest MPG tanks were after I filled up at a different gas station than the cheapest place by me which is a Sam's Club gas station. I am going to have to test filling up at a Shell station and Marathon. We have a Wesco by us which sometimes is the cheapest price.

 

20191126.thumb.jpg.9e814079cbe28ba0381d058e3b4b872b.jpg

 

20191126b.thumb.jpg.6d5c8d8b77223a9b329170bebed5d775.jpg

 


 

  • Like 1
  • Replies 124
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

kenny_r
kenny_r

The one thing they got right though is putting the large fuel tanks on the 6.0 HD’s because I’d hate to fill up every 80 miles [emoji23]

i82much
i82much

have you ever heard of the “Internet?”

Cowpie
Cowpie

Yeah, I am really surprised that GM felt the need to depart from 4.10. It might be from a mpg mindset, but usually that doesn't play out as neat as the folks in cubicles think they will.   

Posted Images

SkidooSteve12 Enthusiast

SkidooSteve12

Posted
Posted

Had to start a new post to continue adding pictures.

 

This is a picture of my trip meter which hasn't been reset yet since the truck rolled off the assembly line. It had quite a bit of idling time when I was test driving it and testing how my trailers hooked up to it. It is right on par with saying 13.2 MPG and my aCar app saying overall MPG is 12.5 with the 0.7 MPG difference which is right about what I see the difference is with each tank of gas, varies between 0.4 and 0.8 so far.

 

IMG_20191125_171749.thumb.jpg.328ab3ed82449b5f2b36cd4ce095410a.jpg

 

 

Regarding the RPM's at cruising speeds, this is a pic of my RPM's with the cruise set at 55 mph on a flat road. And my 25 and 50 MPG best ratings. I never really thought about the engine using more gas if the engine is running below optimal RPM's. Even at 80 MPH my RPM's are just under 2000 I think in 6th gear.

 

IMG_20191125_171626.thumb.jpg.45c3a0409e43ae60188c8c0539ddecd5.jpg

 

IMG_20191125_171547.thumb.jpg.85986dc02c21d09f6b8dfc086ae4ca04.jpg

  • Like 1
Ray Pickle Enthusiast

Ray Pickle

Posted
Posted

Shotgun z71, based on your post regarding your best for 25 mi 50 mi and 400 you are getting good mpg. Those 2 mi. commutes are killing your average as Iam sure you know! Cold engine rich fuel mixtures then early shutdown. I think 12 or 13 mpg on short commutes is the best your going to get

texasnavy05 Enthusiast

texasnavy05

Posted
Posted
12 hours ago, SkidooSteve12 said:

Seeing my truck in the parking lot next to other pickup trucks, I can see why the gas mileage isn't much better because it is so much taller and has a big front end that is pushing a lot of air and taking in a lot of air through the grill. And the stock tires on 20" wheels are huge compared to what we used to run on 2500HD trucks, so that eats up some MPG's and I think that's why some people are getting better MPG's than others. Here is a comparison between sizes and at the bottom what is available for the 2020 HD.

 

 

 

 

 

Does anyone else use the aCar or Fuelly app? I have since I bought my truck and here are some screen shots of my info so far. I have noticed that the 2 highest MPG tanks were after I filled up at a different gas station than the cheapest place by me which is a Sam's Club gas station. I am going to have to test filling up at a Shell station and Marathon. We have a Wesco by us which sometimes is the cheapest price.

 

 

 

 

 


 

 

12 hours ago, SkidooSteve12 said:

Had to start a new post to continue adding pictures.

 

This is a picture of my trip meter which hasn't been reset yet since the truck rolled off the assembly line. It had quite a bit of idling time when I was test driving it and testing how my trailers hooked up to it. It is right on par with saying 13.2 MPG and my aCar app saying overall MPG is 12.5 with the 0.7 MPG difference which is right about what I see the difference is with each tank of gas, varies between 0.4 and 0.8 so far.

 

 

 

 

Regarding the RPM's at cruising speeds, this is a pic of my RPM's with the cruise set at 55 mph on a flat road. And my 25 and 50 MPG best ratings. I never really thought about the engine using more gas if the engine is running below optimal RPM's. Even at 80 MPH my RPM's are just under 2000 I think in 6th gear.

 

 

 

Great write up.  I'm going to start using fuelly.  

 

I wonder what the difference is between the trip mpg and hand calculated mileage?  Does the DIC exclude fuel burned while idling?  My DIC is also consistently higher than hand calculated.

SkidooSteve12 Enthusiast

SkidooSteve12

Posted
Posted
14 hours ago, texasnavy05 said:

Great write up.  I'm going to start using fuelly.  

 

I wonder what the difference is between the trip mpg and hand calculated mileage?  Does the DIC exclude fuel burned while idling?  My DIC is also consistently higher than hand calculated.

Thanks. I used Fuelly's website before when I had a 45 minute work commute one way. Before that I made a spreadsheet that I would fill out after each fill up. lol Yeah I like keeping those kind of stats. Engineering mind always going overboard LOL

 

Some say their DIC matches their hand calculated MPG, but most people will agree that it doesn't match up correctly. Not sure why.

Ray Pickle Enthusiast

Ray Pickle

Posted
Posted

Ok, just returned from first road trip. Cincy to Nashville and back 675 mi. Including a short amount of city driving, less than 20 mi., I hand calculated 16.2 mpg rainstorm on way down cut mileage noticeably according to DIC. It was showing 16.6 prior to rain during first 50 or 60 miles on trip down but dropped to 15.9 in subsequent 200 miles. Rained coming back for majority of drive as well. I think it cost me a solid 1 mpg. But pure speculation, educated guess!

  • Like 2
greatmizzou Enthusiast

greatmizzou

Posted
Posted

I got my computer to eek out 20.0 mpg on the dot for 50mpg average.    Interstate plus some county highway travel rolling hills. 
 

was suuuuper gentle on the accelerator, would take advantage of downslope and coast up hills as light as possible.   59mph looked like the sweet spot for highest mpg.

 

 

  • Like 2
SkidooSteve12 Enthusiast

SkidooSteve12

Posted
Posted
13 hours ago, greatmizzou said:

I got my computer to eek out 20.0 mpg on the dot for 50mpg average.    Interstate plus some county highway travel rolling hills. 
 

was suuuuper gentle on the accelerator, would take advantage of downslope and coast up hills as light as possible.   59mph looked like the sweet spot for highest mpg.

 

 

What size tires do you have?

ShotgunZ71 Senior Enthusiast

ShotgunZ71

Posted
Posted

Had another trip with the 5th wheel over the Thanksgiving holiday. Somehow, I averaged 8.0 mpg on the trip home. Usually is around 7.5 so far in various types of traffic and roads.

cmysstailights Enthusiast

cmysstailights

Posted
Posted

Dam, i average 6.5 towing tt 10k lbs on e85. Was hoping that motor would be doing atleast 9 or maybe 10. Really feel the new trucks need bigger gears.

Sent from my SM-G960U using Tapatalk

greatmizzou Enthusiast

greatmizzou

Posted
Posted
1 hour ago, SkidooSteve12 said:

What size tires do you have?

18" LT275/70 R18E
 

 

I had to really take it easy to get it that high,  people behind me if there were any would not have been happy lol.  
 

More realistic gentle driving is 15mpg average mixed highway use.   Straight highway probably 17mpg

magnum74 Enthusiast

magnum74

Posted
Posted

If they're able to add 1mpg to this truck with such noticeable size, power and capability increases they've done a phenomenal job in my book. The stats on the new 2500 make my 2016 look like a toy.

  • Like 2
ShotgunZ71 Senior Enthusiast

ShotgunZ71

Posted
Posted
6 hours ago, cmysstailights said:

Dam, i average 6.5 towing tt 10k lbs on e85. Was hoping that motor would be doing atleast 9 or maybe 10. Really feel the new trucks need bigger gears.

Sent from my SM-G960U using Tapatalk
 

My previous TT was 9500 lbs and I averaged 8.5 running 87 octane. If you're getting 6.5 running E85, I'd say that's pretty good. A lot has to do with terrain, speeds towing, etc. E85 is good for making power, but crap for getting good mileage. I believe @Cowpie  runs E85 almost all the time on his 6.0 and could be a better source for the power/mileage of E85.

cmysstailights Enthusiast

cmysstailights

Posted
Posted
My previous TT was 9500 lbs and I averaged 8.5 running 87 octane. If you're getting 6.5 running E85, I'd say that's pretty good. A lot has to do with terrain, speeds towing, etc. E85 is good for making power, but crap for getting good mileage. I believe [mention=122677]Cowpie[/mention]  runs E85 almost all the time on his 6.0 and could be a better source for the power/mileage of E85.
Towing in the mountains upstate ny. I have average 3mpg less than 87. Looking to go diesel now

Sent from my SM-G960U using Tapatalk

ShotgunZ71 Senior Enthusiast

ShotgunZ71

Posted
Posted
2 minutes ago, cmysstailights said:

Towing in the mountains upstate ny. I have average 3mpg less than 87. Looking to go diesel now

Sent from my SM-G960U using Tapatalk
 

I can see where that makes a big difference towing. If I were towing more in the mountains, I may have contemplated a diesel again. We tow the 5th about 10 times a year, with 9 of them non-mountains. Some rolling hills, but not too bad. With the gasser, you can let it churn (manually, if needed) in the 3-4k range and be fine in the hills. Sure, your mileage may be less, but you'll be able to maintain with traffic. How do you drive the truck normally? Short trips, mountians, etc? I have a lot of short trips, also, so the gasser was a perfect fit for my needs and uses. Also saved a little money in the process. I had a Duramax and really enjoyed it, but I didn't really work it all the time like they need these days. For where I go and what I do, the gasser does great.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • bwiese
      seat base height *lowering* (base 40/20/40 seat, 2026 1500 WT std cab)

      By bwiese · Posted

      Folks, Have a great new 2026 WT  (std cab, 2.7/4WD) w/base 40/20/40 mech adj bench "fake buckets"  (with lower and upper center console) heavy vinyl seats.  Overall the seats are very comfortable and the vinyl is heavy and appears less likely to 'split out'. Am very tall (6'5")  + a bad back/osteporosis/former hyperparathyroidism so ease/range of movement is a bit restricted.  The truck rides a bit high and I use a nerf step bar w/my left foot to step in, then I put right foot/leg in, drag my butt in  & get seated.  Worked fine in my 2018 RAM quadCab. But I end up dragging my butt over the left raised sidecushsion area of vinyl seat, and due to texture there's fair amount of traction on slide inward.  (ArmorAll didn't improve.) If the seat were even ~1/2" - 3/4" lower it'd be helpful, but base seats just have the forward/backward underseat bail and the side lever for tilt which really doesn't affect seat height.   I really don't want to 'de-puff' the left side sidecushion forming the  fake 'bucket'. I know one company sells 'seat elevator blocks':  but is there a simple way of lowering the height of the driver seat instead?   Thanks Bill W San Jose  
    • bwiese
      on-wheel cellphone control: 2026 1500 WT (2.7L 4WD std cab)

      By bwiese · Posted

      I have a basic 2026 1500 WT  (2.7L/4WD reg cab shorttbed). Comfy, generally happy with electronics/radio - but is there a way I can add switches to steering wheel right-side position (curr. empty) so I can adjust volume, push phone button to voice dial, etc? Bill W San Jose  
    • Tyler Gibbs
      Travel Trailer 2024 2500 HD 6.6 Gas Engine ?

      By Tyler Gibbs · Posted

      The curb weight on a 1 ton crew cab long bed is around 7k lbs.  Now, I don't know where you went to school but 9k is not more than 2x 7k lbs. More than 2x 7k lbs would be 14k+.   With that said, obviously yes you're going to feel a 9k lb trailer when slowing down.  I already said, when accelerating.  When changing lanes?  No.  But if you look at the context of what was quoted, the original person said, "after a mile or two..." which means that would be after the accelerating portion and you're driving a generally steady pace.  Please do learn to read and comprehend.
    • sFrank
      2026 Silverado Range AFM DFM ECU loaction

      By sFrank · Posted

      So I purchased the Range unit for my 2026 and I am seeing different locations suggested for the ECM . Can anyone confirm wither under hood, left side or right side or behind the wheelwell?
    • No F-bdy Bs
      Dave's Auto (custom engine builder) tear down of L8T

      By No F-bdy Bs · Posted

      Like I've said before. Di and Carbon buildup is not that big of a concern. Engine had minimal buildup, and that engine was obviously not super well maintained. Do regular oil changes, and you're gtg as long as the rest of the truck lasts. Also, the High Pressure FP that people ****** about, but can't tell you why.  Now, I wish they'd trash the variable oil pump. No real world issues with them, but I'll gladly eat whatever miniscule MPG it's saving me in favor of more oil at all RPMs.    Curious to see his assessment of the 7.3 compared to the 6.6. I expect he'll praise the port inj, but from a structural standpoint, the 6.6 is as robust as any engine out there.    Not to take away from the 7.3. I feel it's equally as good as the 6.6.     As to heat on the rear cyls, I'd have to see numerous examples before I'd say it's an issue. Especially not knowing the history of that engine. For all is known, they could have blown a rad hose, and ran it hot, and the 2 rear cyls may be the first to get hot in a low coolant situation, but not be an issue aside from that. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...