Jump to content

MPG at 600 miles

2021 HD

By 2021 HD
in 6.6L Gas V8 (L8T)

 Share

Recommended Posts

2021 HD Enthusiast

2021 HD

Posted
Posted

I am getting 12.9 MPG all around town in my 24 6.6 gas job. The truck is saying 12.7. This is with 600 miles on it. If I can get 14 MPG when broken in I will be happy.

Dunn Senior Enthusiast

Dunn

Posted
Posted

I get around 12.3 in 23 model, worse in heavy stop and go

 

Heard in 24s the biggest benefit is towing....otherwise pretty much same

 

My 2022 LT was bit better than  H.C. I have now....not much but lil bit

mrjulian416 Enthusiast

mrjulian416

Posted
Posted

Over a total of 35k miles, I have never reset "trip 2" on the odometer.  Combined calculated is 15.1.  That includes around town, highway trips, occasional moderate and heavy towing.

 

I also glance at the "last 25" calculated mileage from time to time.  Around town that will be 11-12.5.  On highway that will be 18-20.5.  Towing... just don't look.

 

Of course, your mileage may vary, literally.

sigmonster Enthusiast

sigmonster

Posted
Posted

I have a 2024 High country gas with 3000 miles. 

Stop and go driving(city) kills the gas mileage to a 12-13 mpg average.

Driving hard (75-85 mph) on the interstate gives about 14 mpg.  Drafting of slowing down to 70-75 gives 15 mpg. 

Driving 60-65 gives 16 mpg and drafting at 60-65 gives 17 mpg.

Towing 2500 lb at 60-65 gives 11 mpg.

Towing 14,000 lb at 60 gives 7-8 mpg.

 

My mileage has improved after the first 1500-2000 miles and may get a little better.

Zero oil usage and the oil is still very light brown.

 

The truck is not quick, but plenty of acceleration when needing to merge (unloaded).

It pulls a 14,000 lb boat remarkably well--I did add the Timbren axle stops so I have very little squat or bouncing.

 

Overall, I love the truck

  • Like 1
KARNUT Senior Enthusiast

KARNUT

Posted
Posted

It would be a great comparison to see what a 1/2 tons gas mileage is with a max trailing package. Especially for people who tow under 12K and do it less than 1/2 the time. My 14 GMC had a trailer package and got 22 mpg at 72 mph empty. 

  • Like 1
sigmonster Enthusiast

sigmonster

Posted
Posted

I had a 2017 Sierra with the 6.2 and max tow.  Very quick truck and great towing 5-6,000 lb.  It got 19 mpg driving hard (75-85) and over 20 mpg driving 70-75, but that was using either premium or 89 ethanol free. It got 10-12 mpg towing a 5,000 lb boat 75 mph.   It was a great truck, but not up to towing my new boat.  I will say my new 2500 rides more smoothly and quietly; it is just harder to park-LOL.

UWSkier Enthusiast

UWSkier

Posted
Posted
On 9/12/2023 at 5:48 AM, sigmonster said:

I have a 2024 High country gas with 3000 miles. 

Stop and go driving(city) kills the gas mileage to a 12-13 mpg average.

Driving hard (75-85 mph) on the interstate gives about 14 mpg.  Drafting of slowing down to 70-75 gives 15 mpg. 

Driving 60-65 gives 16 mpg and drafting at 60-65 gives 17 mpg.

Towing 2500 lb at 60-65 gives 11 mpg.

Towing 14,000 lb at 60 gives 7-8 mpg.

 

My mileage has improved after the first 1500-2000 miles and may get a little better.

Zero oil usage and the oil is still very light brown.

 

The truck is not quick, but plenty of acceleration when needing to merge (unloaded).

It pulls a 14,000 lb boat remarkably well--I did add the Timbren axle stops so I have very little squat or bouncing.

 

Overall, I love the truck

This is about what I am seeing in my 2024 LTZ with 7000 miles.  I got 19 MPG driving at 60 MPH with a tailwind once so far, but most everything else jives with what you've posted.

 

Comparing to my 2016 Denali half ton 4wd with 5.3L, I get about 2 MPG worse in everyday driving, but about 1 MPG better towing in pretty much all conditions.

  • Like 1
2021 HD Enthusiast

2021 HD

Posted
  • Author
Posted

I forgot to say that 12.9 mpg is all around town but 1/2 the time having around 800 lbs in the back. the most in the back i have had so far is 2200 lbs. 

  • Like 1
Jettech1 Senior Enthusiast

Jettech1

Posted
Posted
4 hours ago, 2021 HD said:

I forgot to say that 12.9 mpg is all around town but 1/2 the time having around 800 lbs in the back. the most in the back i have had so far is 2200 lbs. 

I would say you are right in the normal range.  These trucks are heavy as hell, so getting say 13 to 14 around town unloaded sounds quite normal.

  • 8 months later...
BCGM Enthusiast

BCGM

Posted
Posted

My brain matter is shrinking in my latter years . When you quote MPG that is for a US gallon which is smaller than a Canadian gallon .

 

#1 Am I  right in thinking that the MPG would not be the same or am I confused ?

 

#2 What would your fuel consumption be if you posted it as   Liters per 100 Kilometers as Fuel  economy is expressed here in Canada    L/100Klm  ?

Thank you 

Capt Bob Enthusiast

Capt Bob

Posted
Posted
22 hours ago, BCGM said:

My brain matter is shrinking in my latter years .

#2 What would your fuel consumption be if you posted it as   Liters per 100 Kilometers as Fuel  economy is expressed here in Canada    L/100Klm  ?

Thank you 

Using a conversion calculator 12 MPG (about what I get around town) converts to 19.6 liters per 100klm

BCGM Enthusiast

BCGM

Posted
Posted
1 hour ago, Capt Bob said:

Using a conversion calculator 12 MPG (about what I get around town) converts to 19.6 liters per 100klm

Thanks Capt Bob . I think I'm getting better than that but will check next time I'm in the truck as I'm not driving it much as it is a thirsty beast   ,LOL ! I will post a update 

lineman1234 Enthusiast

lineman1234

Posted
Posted (edited)
On 9/11/2023 at 6:46 AM, mrjulian416 said:

Over a total of 35k miles, I have never reset "trip 2" on the odometer.  Combined calculated is 15.1.  That includes around town, highway trips, occasional moderate and heavy towing.

 

I also glance at the "last 25" calculated mileage from time to time.  Around town that will be 11-12.5.  On highway that will be 18-20.5.  Towing... just don't look.

 

Of course, your mileage may vary, literally.

I dont see if it is a gasser or diesel? I know its an older post, but the highway mileage seems to good to be true.

 

I drive very nice and its flat hear. Almost 10,000 miles on my 6.6 gasser and i havent gotten 17mpg on a tank yet, mostly rural 55-60mpg roads. I also havent gotten a tank of non ethanol hear either. Ethanol meaning 10%, not E85.

 

Not much of town driving around hear, so i dont know on that.

 

But, tank to tank, fill ups with diesel being more than gas, its still cheaper to feed my gasser than my last diesel. 

Edited by lineman1234
Dunn Senior Enthusiast

Dunn

Posted
Posted

if I stayed on highway I would get 17 mpg in so cal, 21 is my best from Burbank to Long beach no traffic before i hit city streets.....driving 60-65, but always have to mix it with city

 

on trip home from dealership I was at 17 plus on new motor from Phoenix to LA, and I was hauling ass for good portion late at night

 

problem is my area is littered with stop signs every block so its 8-9mpg in town

 

the computer isn't far off real world calculations.....few tenths maybe

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

    • Chuck FB
      first oil change - 2026 2500HD gas

      By Chuck FB · Posted

      Does your dealer charge you for the tire rotation on top of the oil change price ?. I haven't had any service work done at my dealer yet other than when I brought it back soon after owning it to have the front end aligned to correct the steering wheel being off center a bit. Oh they called me at least twice hounding me to bring it in for an oil change and pushing a 300.00 package of oil change and tire rotation and whatever other quick simplistic checks they would do. Only going off of what a friend gets charged for his half ton for the basic oil change and its the same amount of oil as the L8T holds, it was about 150.00. Once one buys a set of tires from most shops these days or so I believe, they will do free tire rotations and some do free tire balancing as well as free tire repairs.    Certainly doing a tire rotation is no five minute job, and definitely not at home but because I run a set of winter tires on their own wheels, I swap them at home and its a one tire at a time deal because of the tire season swap although I jack up the rear and do it and drop it back down and then raise the front and do them and coordinate the tire rotation into that process for both sets of tires. I am using a floor jack though and if I need to raise both ends at once I use a couple sets of jack stands to have all four tires off the ground. I use either an air impact or battery impact and have electric impact as well so no shortage there of easy methods to spin the lug nuts, and then retorquing the lug nuts. None of it goes quick though but my wages are cheap though ... zero. I live an hour out of town, its easier just to do things like that myself than waste a bunch of time in town and having to make an appointment and probably a special trip and sit there at the tire shop waiting for them to get my vehicle in and get it done and not screw something up in the process. 
    • mrbflat
      Clunk when coming to a stop... driveshaft/slip yoke? Mechanic couldn't recreate it

      By mrbflat · Posted

      I do have the 8 speed.  Interestingly enough, after driving my truck for the past 2 days now, I have not had the clunking issue at all!  I am beginning to think it may have been suspension/leaf spring related, and somehow when the shop put my truck on the lift to do their initial inspection, it relieved some built up tension/pressure that was causing my problem.  I swear it felt I was a bull rider on a bucking bull the way the truck would almost rock back and forth slightly before the big thud/clunk when coming to a stop.  I am hoping I got lucky here and it's gone for good.
    • Pryme
      first oil change - 2026 2500HD gas

      By Pryme · Posted

      Bring it to discount tire. They do free rotations even if you didn’t buy your tires there. I didn’t believe it until I tried and they did. You can tip the employee if you would like 
    • Grumpy Bear
      The Peckish Synapse

      By Grumpy Bear · Posted

      Best part of this video is how it resets expectations. Wonderfully done piece. It also made clear a few points I've made from day one. Detergent oils DO NOT KEEP A MOTOR CLEAN at the recommended or longer change intervals. They just get dirty slower than a non-detergent oil and there isn't spits difference between them on this point if they carry the DEXOS license. Great thing about the license that gets missed is it assures CONFORMITY even it that means a low bar.    One thing he did not talk about that I paused on an magnified was the condition of the oil ring separator. Besides a stuck ring a plugged separator and land drain back is huge when it comes control. We see in short order improvement in control IF that is the problem.    Another item I took exception to and he did not make plain was the condition of the timing chest and under valve cover having something to do with indicating piston cleanliness. Schaeffer's Oil makes that same omission in their million mile Ford video. I'm guessing he has never torn down a Red Line HP, AMSOIL SS motor that has been on that diet from the get. What he showed in the video was a good deal of varnish. Something totally absent in Peppers 165K cover off look. I smiled because he did his at the same milage.    He also makes the mistake of assuming oil temperatures in the pan are the temperature all over the motor even though he makes note of the piston being the hottest part of the engine. that baffled me a bit.    I can tell you from personal experience and witnessing teardowns of family motors that even oils of the 1960's would keep them squeaky clean when OCI's were 1500 to 2000 miles without exception. At 3K and above you get what he experienced and the longer you leave it the quicker to gets to the junkyard.    I think his is missing a opportunity not tearing it down again when he's done killing it. Time would be his only cost. 
    • Z45
      GM discontinuing interior parts on a 5YO vehicle??

      By Z45 · Posted

      Very often the part number on the trim part is just for the vendor order/assembly plant and will not show up in the parts system.  They won't make a bunch of extra parts that were not ordered. Keep in mind, lots of these parts were made to be "just in time" parts meaning they were dedicated to a vehicles ordered and sequenced for assembly.       Also, trim parts will often say, paint to match.     

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...