Most get in the 15-20 range running empty, a few get low 20's. You need to share more of the details of your truck to get more meaningful feedback, especially the year.

 

Reason for the question is I’m looking at possibly getting rid of my 1500 for a Duramax. I’ve heard lots of different numbers in terms of fuel mileage. I’m most likely looking at the 2500 13-14’s and 15-16’s. I’m a fan of the LML engine. 2 different body styles, but planning on going with a Denali.

 

I went from a 2017 1500 with a 4.5" lift and 33s to my 2015 2500 and I don't regret it one bit.

I get way better power, a much more capable truck, and I get the same and better fuel milage. With the level my 2500 is the same height as my 1500 was with the lift on it.

My hand calculated fuel milage, with the level and 35s on it (speedo is corrected) I get an easy 21mpg at 70mph on the highway. More if I go slower. Around town I get around 14ish depending how I drive. Thats empty of course.

My 1500 I was lucky to see 19mpg on the highway if I kept it 65mph or less. Around town was about the same 14ish mpg.

 

I misunderstood, my bad. My LML is a pig, about 10,000#, CCLB 4x4, steel flatbed with 4 corner boxes, My typical empty highway mileage is about 17.5. If I keep it down to about 70mph, I've been seeing between 18 and 19 lately.

 

Asking diesel owners what kind of mileage they get is like asking fishermen how big are the fish they catch.

 

Good point. You oughta see the whopping largemouth I just landed, weighed 20 pounds if it weighed an ounce.

Seriously, when guys share their mileage you do need to be sure its not from the DIC. My DIC routinely shows 20-22mpg. Kinda makes you feel good until you remember it's just BS.

 

I bought my 15 Denali and drove it back from San Antonio to west-central Indiana, just a hair over 1200 miles. On the trip coming home, actual hand-calculated mileage was 17.5-19mpg running 80-85mph on the open interstate. I only had it home a few days before it had an emissions problem and I rolled into the delete category. This truck is stock other than dpf/def delete and the tow tune- supposed to be about 60horse. Since then, its been pretty consistently 16.5-17mpg driving back an forth to work on highways, and up to about 18mpg on a couple trips that we've gone on with mostly interstate driving

 

So your MPG actually went down after deleting?

 

My lly get 26 running 55mph with no wind, 24 running 60, 22 running 65. It drops about 1 mpg for every 5 mph of wind.

 

My lly get 26 running 55mph with no wind, 24 running 60, 24 running 65. It drops about 1 mpg for every 5 mph of wind.

Is this hand-calculated or going off the dic, because I don't believe these numbers to be accurate

 

I don't know if it can actually be compared to what I got before deleting it, because that was literally a 1200mile trip with the cruise set on the interstate. I didn't really even get to drive it after I got home with it before I encountered the problem. But, from my experience with three LBZ trucks and then this truck- yes, the mileage actually went down after deleting and tuning

 

I get 16 city driving and 20 hwy. I haven't towed yet so don't know.

 

2012, 2500, crew cab regular bed, 4x4, last weekend got 18.1 hand calculated. Was traveling pretty light with only my dad, my wife and a dog. Was doing 70 to 75mph depending on the limit. Truck has aftermarket dp and 4 inch exhaust. Egr has been turned off but not removed, with single tune.
Before deleting I was only seeing about 14.5 calculated on the highway. Currently I see that 14.5 to 15.3 calculated for around town.

Those are just what I have experienced. But every truck is different. Tires and wheels, fluids, lift kit, all play a factor in mileage.

Sent from my Pixel 3 XL using Tapatalk

 

I avg 15 mpg hand calculated. 1/3 of my driving is in town driving. Bone stock 4 door 4x4

 

👍That’s a little more realistic (15) mine was around 14.5-15 stock, deleted with the same wheels and tires 14.5-15.
Now with larger wider tires with speedo calibrated even more deleted 12.0-13 depending if I have a little more hiway driving. These numbers are solo no towing, towing 13,500 then we‘re talking 9-10 round trip.

 

On my 2008 2500 LMM 4WD purchased new, I have always filled up right to the top of the neck (book says don't do that). That way, I always know exactly what my fuel usage was. I consistently add a gallon more than DIC shows. My gas gauge is at the bottom of the needle on a 20 gal fill up. That is a 5% error low on fuel used (DIC used19) and high error on DIC mpg. I have three different vehicles I use on a 135 mile trip several times a year. The round trip mileage is different on the identical road trips for the three vehicles. !0 miles between low and high, third is right in middle. I really don't know if I drove 264, 269 or 274 miles round trip. All have OEM recommended tire sizes and the truck had original tires until recently. I don't particularly worry about the difference. The cars (over 10 yrs. old) get easily near mid 20's, driving speed limit with only city driving being through towns on the trip. Truck gets 19 at 70, 21 at 60 almost always with A/C on and no severe winds either way. Around town with traffic light fuel waste, truck gets 14 to 17. I haven't forgotten the $100 fill ups back when the truck was low mileage compared with today at less than half that. TDN

 

I get around 16 miles per gallon driving mostly city driving. I did a 250 mile trip a couple weeks back and averaged 21 miles per gallon. So I get 21 Hwy 16 city.

 

Mine is a 2020 2500 L5P Crew cab standard box, with 5800 miles total. At fill ups I’ve hand calculated only a few times and found it to be roughly 1 mpg lower than the DIC claims.

The DIC claims total mileage for 5800 miles so far, at 17.0 mpg.

True mileage with mixed driving (mostly highway, a few mountain passes, both empty and towing 3k to 8k lbs.) per tank is about 16 mpg.

The trailering app tracks individual trailer mileage if a profile is set. For my 3000 lb cargo box trailer it says 16.2 avg. For the flatbed at 8200 lbs it says 12.0 avg.

Empty highway the DIC claims is 23 mpg, but that varies plus or minus a couple depending on speed.

In this truck, horsepower is both abundant and fun, but costs fuel, as it does in anything. Its surprising how quickly it will accelerate, even up a grade while towing heavy, but if you’re watching the real-time mileage you’ll see it dip to low single digits. Down the other side though and it pegs at 99 mpg.

 

I just hauled 4h trailer with LQ from CO to TX about 1200 miles. 2020 3500 DRW. Just below 9 mpg per DIC. Tremendous power just worried a bit about temps due to emissions bs.

 

Best I have gotten is 20.7 on the highway. Not great around town at 12-13. It's not an everyday driver though so I don't count on it for that. I'm at about 8mpg pulling my enclosed 7x14 trailer at 75mph.

 

On my 2020 checked the DIC by filling up to the top of the neck shaking the truck a little to get rid of air pockets fill to top again a few times. Mine was off about 2% and 1% of that was tire size change. Verified the speed and change with my GPS program on the phone. I hauls loads from time to time but no trailer needed yet. Some of this is reflective of idling for 4 to 6 hours at the ranch in 110 heat (AC is a must) or sitting in traffic during snow/ice storms last winter traveling to the ranch in NM, highway during shutdowns with the AC or heat on and yes off road in 4wd as well.

Gives a good idea of the total not just a trip or two or three.. So far very impressed--all stock except 35x12.50-20 Ridge Grappler tires installed the day after I bought the truck.

 

Hey all, new to the forum here.

I was wondering, what are you guys seeing for fuel mileage? Deleted, stock, it’s all good! Curious to hear what you guys are seeing.

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I see you typed "it's all good!". Not clear what you are trying to communicate with the expression "it's all good!". Is that like "lol" and "awesome" and "oh my god"....? (hey...folks...i am not making fun of the "Valley Girl" types....they have a right to come in here and ask for our help). (perhaps he or she means to tell us what we "red-necks" would say "my truck is running well"....?)

My figures may not be of much use to many of the folks in here, because we bought our truck to use as a truck (for a daily driver we have a Toyota RAV 4).

Used as a truck means we use it for hauling heavy stuff (can't imagine why anyone, (IF they have a choice) would use one of these monsters as a daily driver).

Anyway, I have found my truck's fuel mileage is VERY dependent on both the load i put on it, and even more important, the type of load.

For example, in some parts of the country the roads are pretty much level. On "pretty much level" roads, with just our 800 lb. Wave Runner ( jet ski) in the bed, when the wind is light, like the others reporting in here I see around 17.5 mpg.

On "pretty much level" roads, "bumper pull" towing either of our approx. 11,000 lb. trailers, if the wind is light, and I stay around 65 70 mph, I see around 13 mpg.

In some parts of the country, we have roads with long failry steep grades....for example, tha winding stretch coming uphill out of the Temple Bar Marina to U.S. 93 in northern Arizona, when pulling our boat, will take us down to 5-8 mpg. Same for those "killer" grades on Interstate 40 going uphill either direction out of Needles, California where you climb back up to the higher country.

Wind direction is a significant factor - the stronger the head-wind, the worse the mileage...a strong head-wind can knock off 3-6 mpg...a good tail-wind will do the opposite.

If you are looking for good, economical fuel mileage as a daily driver, & you have no need for the spectacular pulling power of a diesel, may I respectfully suggest a passenger car like what we drive when not in need of Duramax capability.

 

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I see you typed "it's all good!". Not clear what you are trying to communicate with the expression "it's all good!". Is that like "lol" and "awesome" and "oh my god"....? (hey...folks...i am not making fun of the "Valley Girl" types....they have a right to come in here and ask for our help). (perhaps he or she means to tell us what we "red-necks" would say "my truck is running well"....?)

My figures may not be of much use to many of the folks in here, because we bought our truck to use as a truck (for a daily driver we have a Toyota RAV 4).

Used as a truck means we use it for hauling heavy stuff (can't imagine why anyone, (IF they have a choice) would use one of these monsters as a daily driver).

Anyway, I have found my truck's fuel mileage is VERY dependent on both the load i put on it, and even more important, the type of load.

For example, in some parts of the country the roads are pretty much level. On "pretty much level" roads, with just our 800 lb. Wave Runner ( jet ski) in the bed, when the wind is light, like the others reporting in here I see around 17.5 mpg.

On "pretty much level" roads, "bumper pull" towing either of our approx. 11,000 lb. trailers, if the wind is light, and I stay around 65 70 mph, I see around 13 mpg.

In some parts of the country, we have roads with long failry steep grades....for example, tha winding stretch coming uphill out of the Temple Bar Marina to U.S. 93 in northern Arizona, when pulling our boat, will take us down to 5-8 mpg. Same for those "killer" grades on Interstate 40 going uphill either direction out of Needles, California where you climb back up to the higher country.

Wind direction is a significant factor - the stronger the head-wind, the worse the mileage...a strong head-wind can knock off 3-6 mpg...a good tail-wind will do the opposite.

If you are looking for good, economical fuel mileage as a daily driver, & you have no need for the spectacular pulling power of a diesel, may I respectfully suggest a passenger car like what we drive when not in need of Duramax capability.

My God---more ramblings from the infamous 6686L who is so far out there he does not even know where he is Bless His Heart. Feel sorry for him actually. He always in almost every post tells you either you do not need the truck or you do not know what you are doing.

 

My L5P on 305/55R20 wheels with a 3.5" lift averages 14 as well. Highway at 70mph I get 18 to 22, depending on weather and traffic. Towing a 13k lb TT camper I am seeing 10.5 mpg at 65mph on flat roads in good weather.
[/QUOTE]

Have you spent anything on it to get that kind of mileage? Single wheel?

My new to me 2018 dually showed low 19's and 17.5 on my first 2 trips which was the first tank of fuel. I was a bit disappointed when I fueled up last night and that tank got 15.1 mpg. The DIC readings seem about normal, way high.

 

Have you spent anything on it to get that kind of mileage? Single wheel?

My new to me 2018 dually showed low 19's and 17.5 on my first 2 trips which was the first tank of fuel. I was a bit disappointed when I fueled up last night and that tank got 15.1 mpg. The DIC readings seem about normal, way high.

I have not spent any money on it performance-wise, and yes it's a SRW. I do drive it like there's an egg behind the skinny pedal, though. Those numbers are hand calculated, and were summer fuel and driving conditions. I have owned this truck since July, and the numbers are going down with the cold weather. My last tank was hand calculated at 13.96 mpg but the DIC showed 15.1. The majority of my drive on a daily basis is 55mph roads, so that helps too. Not much stop and go.

 

Yeah I know the colder weather isn't helping anything. It's just a bit disappointing when I got 18+ with my LML 2 weeks ago running 75-80 and last night I was tickling that egg with my right foot at 65-70 mph and only got 15 mpg. And the same LML would straight up smoke this 2018 in a drag race. I certainly hope this "new" truck pulls the tongue out of a trailer!

 

Remember, the L5P dead pedal is real. It feels super doggy, but that power really is there. I couldn't believe how different it felt pulling our camper with the L5P compared to my LMM. Not as big of a difference for you coming from the LML, though.

 

It's more than just deal pedal, the LML had a deal pedal but when it finally roared to life it would pin you back to the seat. The L5P accelerates more like my 2002 Le Sabre V6, all the way up to highway speed. And it's not like I need it to be a drag racer, I just hope when I finally get hitched up, it amazes me because I certainly haven't been wowed for all the money so far. And it appears empty mileage is lower, still hoping maybe towing mileage will be at least par or better. I will give it the interior is very comfy and convenient and the ride is a little better. The steering seems to be the single finger type as well. Oh well, I'll quit corrupting this fuel mileage thread any further.

 

I use it as a daily driver simply because it's what I want to drive.

 

I drive mine daily as most here do as well, (most days as well) poor guy cannot just leave it alone. People read what he posts and laugh at him because it just does not make sense. You should go back and read some of the rants he has gone into!

 

I get 14.3 MPG for last 10K miles, hand calculated. My DIC mileage is 1 MPG lower. My truck is a dually with ladder rack and 2 big toolboxes. It weight 9,080 lb.