[Lucky Dog]

The truth according to Fuelly.

 

[timmytime]

I get a kick out of people that ask why their gas mileage is so bad, then go on to say how they "only" do 75 mph, etc.
I'm old, and I drive like I'm older yet. I see 30 mpg frequently. You can have speed, or fuel economy, but not both.

 

[ncskibum]

I'm old too but like to drive as if I'm still a teenager on mom and dad's insurance! Of course, if I really drove like that, I wouldn't have VW and Ram diesels.

 

[kmcintyre]

I've got the 3.92 gears and the GDE tune didn't help my mpg at all I have a camper on full time and it made no difference. If it prevents other issues I guess I'm ok with that but the improvements didn't work out for me. I get 20mpg.

 

[Tarheel]

2016 Laramie 3.92 4x4 with Falken Wildpeak AT3 tires in foothills and Piedmont NC. With SRA Goodyear I average 26-27mpg. 50/50 highway and city. With the Falkens 24-25.
I once saw 29 on a long highway drive, but that was the best I ever got. That's doing 65-70mph on highway. I dont usually go over 70mph.

 

[Bat Koce]

Jtyson if you put the stock tires back you will easily gain 2-3 mpg.

With my style of driving in slow trafic I get better MPG then doing 75MPH on the HWY. It was the same thing with the two TDI's I owned before the ED.
I have almost 50K miles and hand calculated average of 29mpg, but I drive like an old lady. 4X4 outdoorsman 3.52 and stock tires.
I drive for the RECORD.
I know there are guys here who get better than my MPG, but that can only motivate me.
I live in Vegas and when the night temps drop Bellow 50F I plug the heater in. That also helps a lot in the morning.
Got a 800W Thermoking auxiliary coolant heater to warm the engine and cab faster.
I am not sure if that helps a lot.



Sent from my SM-N960U using Tapatalk

 

[jtyson]

2016 Laramie 3.92 4x4 with Falken Wildpeak AT3 tires in foothills and Piedmont NC. With SRA Goodyear I average 26-27mpg. 50/50 highway and city. With the Falkens 24-25.
I once saw 29 on a long highway drive, but that was the best I ever got. That's doing 65-70mph on highway. I dont usually go over 70mph.

I have considered that the tires I run may affect it. I'm due for a new set. I may look around before buying more of these Michelin Defenders.

depends on the wind , and speed , READINGS HERE = NO WIND , MAYBE LITTLE TAIL WIND ??
when possible witout becoming a '' cholesterol of the road blocking arteries '' I put cruise anywhere between 107 or 111 KPH ,
I see 6L / 100 km , goes to 5 , goes to 7 , depending on little ups or downs on the road .

''''' GDE Tuned '''''''''''' , 3.55 rear , cruise control ON , << ** EVIC readings >>, so seeing 7L/100km could be 7.8 , there is no decimal on EVIC .
(( when I see 6L / 100 Km , it could be 6.9 so lets say 7 )) puts me in Unicorn territory ...
when I see 5 , and I do see 5 , I'm in the high 30s .

<<<<<<<< some days, same cruise control speeds , and I get 10L or 11 L at best , it is the wind ....>>>>>>>

numbers translated to MPH = 107 and 111 KPH = 66.5 and 69 MPH
numbers translated to US gallons =
8L / 100 km = 29.4 MP US gallon
7L / 100 km = 33.6 MP US gallon
6L / 100 km = 39.2 MP US gallon
5L / 100 km = 47 MP US gallon
---
10L / 100 km = 23.5 MP US gallon
11L / 100 km = 21.5 MP US gallon
---------------------------------------------------------------
ALL true Numbers //
IMPORTANT DETAIL : with engine UP AT TEMPERATURES , it's a diesel , numbers not optimal until warm .
short drives will not give you top numbers .
---------------------------------------------------------------

Lots of detail there. Possibly entirely irrelevant, but my limited driving experience in Canada from Montreal to Toronto then back to the states through Michigan. I was in my 08 duramax, and due to the speed limit there being 100km/h pretty much everywhere it seemed, I got something like 24.5mpg in my extended cab short bed duramax 4x4 with 33" BFG all terrains. EFI live tuned and deleted, but otherwise basically stock. I thought maybe you Canadian folks might be getting better fuel than us down here in the SW USA. That was easily 5mpg more than I got anywhere else, even doing the same speeds. In my 06 Duramax, pulling a vintage silver streak trailer from Oregon to California, I got 23.5 MPG coming down through the Mt Shasta area due to the help of a perfectly placed tail wind so that definitely lends credibility to that theory.

I warm my truck up before I drive if it is below 50 degrees F. This I figure is probably a non issue either way because 10 minutes idling wastes fuel, but less time driving cold is more efficient.

On my normal days I drive about an hour one way at 75-80mph. Then short jaunts of a few miles 5-6 times until it is time to drive home an hour at 75-80mph.

2 days a week my morning drive is about 4 hours at 75-80mph then a few miles 5-6 times, then drive the 4 hours back home at 75-80mph.

Weekends it is all short in town drives of less than 20 miles for the most part.

I bet if you ask your buddies their Johnson is bigger than yours too! If your buddies are saying they are beating mid 20's on the hwy with lifted cummins and bigger tires they have some serious money invested in mods and are hypermiling kings.

I was the one who installed tunes on these trucks. Helped with some of the mods, but most are pretty basic tune and delete set ups. I've driven them myself. It is hard to believe, but empty, pushing 35s or 37s they are getting 24-28 pretty consistently on highway miles. Proper tuning and getting rid of restrictions is a night and day difference on those. Though frankly, even if that were exaggerated a few mpg, would I rather drive an Eco with less than 300hp, tow limits under 10k and a less proven design for longevity (Fiat vs Cummins)? Not really. But I've got the eco currently, so until I buy another truck, I'm making the best of it.

I get a kick out of people that ask why their gas mileage is so bad, then go on to say how they "only" do 75 mph, etc.
I'm old, and I drive like I'm older yet. I see 30 mpg frequently. You can have speed, or fuel economy, but not both.

I'm not saying my mileage is bad. Just that it isn't what everyone says. For any truck, north of 20mpg is pretty good. And I don't only drive 75mph. But I drive the speed limit or pretty close with the flow of traffic. If the speed limit is 75mph traffic is generally flowing between 75-85mph. It is hazardous to be the guy doing 65mph in that clogging everything up.

 

[phprof]

I have a 2014 Bighorn with 3.92 gear, 4x4. I live in UP of Michigan so deal with cold weather for about 4-6 months and snow 3-4 months. Cold starts, hilly drive, kills mileage. Pull a 22 ft 5000 lb trailer during the summer for about 2k miles-ish. My long term average on fuelly is 20.4 mpg. My high was about 28 mph on a 120 mile round trip down to my kids camp and back. Road was mostly quiet so locked in at the speed limit (55 mph). It was warm and sunny. During the heart of cold I can dip as low as 18 mpg. Running about 20 mpg this last two fills.

 

[jtyson]

Jtyson if you put the stock tires back you will easily gain 2-3 mpg.

With my style of driving in slow trafic I get better MPG then doing 75MPH on the HWY. It was the same thing with the two TDI's I owned before the ED.
I have almost 50K miles and hand calculated average of 29mpg, but I drive like an old lady. 4X4 outdoorsman 3.52 and stock tires.
I drive for the RECORD.
I know there are guys here who get better than my MPG, but that can only motivate me.
I live in Vegas and when the night temps drop Bellow 50F I plug the heater in. That also helps a lot in the morning.
Got a 800W Thermoking auxiliary coolant heater to warm the engine and cab faster.
I am not sure if that helps a lot.



Sent from my SM-N960U using Tapatalk

I have stock wheels and stock size tires. 275/60r20. The hypermiling for me costs me more than it would save. My time is worth more than the few MPG saved so I can't justify doing 20mph under, coasting everywhere, etc. Plus, I like my creature comforts. While I sit in my truck doing paperwork, I leave it idling. Sometimes for 5 minutes, and sometimes for an hour. I know that eats up some of my fuel. Not sure how efficient these are at idle.

I have a 2014 Bighorn with 3.92 gear, 4x4. I live in UP of Michigan so deal with cold weather for about 4-6 months and snow 3-4 months. Cold starts, hilly drive, kills mileage. Pull a 22 ft 5000 lb trailer during the summer for about 2k miles-ish. My long term average on fuelly is 20.4 mpg. My high was about 28 mph on a 120 mile round trip down to my kids camp and back. Road was mostly quiet so locked in at the speed limit (55 mph). It was warm and sunny. During the heart of cold I can dip as low as 18 mpg. Running about 20 mpg this last two fills.

We are cold enough to get winter blend fuel here, but nowhere near the weather issues you've got. We do have the hills though. Albuquerque sits at about a mile above sea level and I drive all through the rockies.

 

[MAS]

I have considered that the tires I run may affect it. I'm due for a new set. I may look around before buying more of these Michelin Defenders.


Lots of detail there. Possibly entirely irrelevant, but my limited driving experience in Canada from Montreal to Toronto then back to the states through Michigan. I was in my 08 duramax, and due to the speed limit there being 100km/h pretty much everywhere it seemed, I got something like 24.5mpg in my extended cab short bed duramax 4x4 with 33" BFG all terrains. EFI live tuned and deleted, but otherwise basically stock. I thought maybe you Canadian folks might be getting better fuel than us down here in the SW USA. That was easily 5mpg more than I got anywhere else, even doing the same speeds. In my 06 Duramax, pulling a vintage silver streak trailer from Oregon to California, I got 23.5 MPG coming down through the Mt Shasta area due to the help of a perfectly placed tail wind so that definitely lends credibility to that theory.

I warm my truck up before I drive if it is below 50 degrees F. This I figure is probably a non issue either way because 10 minutes idling wastes fuel, but less time driving cold is more efficient.

On my normal days I drive about an hour one way at 75-80mph. Then short jaunts of a few miles 5-6 times until it is time to drive home an hour at 75-80mph.

2 days a week my morning drive is about 4 hours at 75-80mph then a few miles 5-6 times, then drive the 4 hours back home at 75-80mph.

Weekends it is all short in town drives of less than 20 miles for the most part.


I was the one who installed tunes on these trucks. Helped with some of the mods, but most are pretty basic tune and delete set ups. I've driven them myself. It is hard to believe, but empty, pushing 35s or 37s they are getting 24-28 pretty consistently on highway miles. Proper tuning and getting rid of restrictions is a night and day difference on those. Though frankly, even if that were exaggerated a few mpg, would I rather drive an Eco with less than 300hp, tow limits under 10k and a less proven design for longevity (Fiat vs Cummins)? Not really. But I've got the eco currently, so until I buy another truck, I'm making the best of it.



I'm not saying my mileage is bad. Just that it isn't what everyone says. For any truck, north of 20mpg is pretty good. And I don't only drive 75mph. But I drive the speed limit or pretty close with the flow of traffic. If the speed limit is 75mph traffic is generally flowing between 75-85mph. It is hazardous to be the guy doing 65mph in that clogging everything up.

Seriously if you have the knowledge and means to consistently get the HD’s to 28 mpg you should have your ecodiesel producing excess diesel and routing it to a tank in the bed to sell. That info wasn’t worth the unicorn tears it took to print.

 

[RansomT]

My signature has my fuelly MPG over the past 25,625 miles. The truck is a 4x4 Crew with the 6.4 bed. I ALWAYS use my cruise control and try to keep my speeds in the mid-60s. Plug the truck in when overnight temps are lower than 50F, warm the truck up for a few minutes when the temp is below 20F. I realistically drive 85% highway and 15% urban. Commute is mainly I-75 close to 60 miles round trip. I've also been know to shut the engine off when setting at some of our 2-3 minute traffic light waits.

For the folks who say that they MUST drive 75-80 mph because they would get hit. My ~30 mile one way commute is on a busy section of I-75, a LOT of traffic travels in that 75-80 mph range. I never had an issue driving at 64-65 mph. And if I did get hit, I would be driving a new truck much more often. But considering the speed difference, 15 mph, I doubt if much damage would happen. BTW, if you do the math, the time difference between 75 mph and 65 mph is about 2 minutes for my commute.

 

[jtyson]

Seriously if you have the knowledge and means to consistently get the HD’s to 28 mpg you should have your ecodiesel producing excess diesel and routing it to a tank in the bed to sell. That info wasn’t worth the unicorn tears it took to print.

What?

My signature has my fuelly MPG over the past 25,625 miles. The truck is a 4x4 Crew with the 6.4 bed. I ALWAYS use my cruise control and try to keep my speeds in the mid-60s. Plug the truck in when overnight temps are lower than 50F, warm the truck up for a few minutes when the temp is below 20F. I realistically drive 85% highway and 15% urban. Commute is mainly I-75 close to 60 miles round trip. I've also been know to shut the engine off when setting at some of our 2-3 minute traffic light waits.

For the folks who say that they MUST drive 75-80 mph because they would get hit. My ~30 mile one way commute is on a busy section of I-75, a LOT of traffic travels in that 75-80 mph range. I never had an issue driving at 64-65 mph. And if I did get hit, I would be driving a new truck much more often. But considering the speed difference, 15 mph, I doubt if much damage would happen. BTW, if you do the math, the time difference between 75 mph and 65 mph is about 2 minutes for my commute.

For a 30 mile drive 65-80 is a difference of a about 6 minutes. And yeah 6 minutes isn't a ton. For me that difference would waste about a half hour per day. Some days a little less, on my long days, it would cost me an extra 1.5hrs. Admittedly, I could shave 5 minutes here and there and probably make it up elsewhere in life I'm sure.

But flow of traffic again is the concern here. One person deciding to do 15mph less than everyone else can cause accidents. And it's not always the turtle that's involved. It's the guy doing 90 hitting the guy doing 75 in the fast lane trying to pass the guy doing 15 under. Then an innumerable amount of people potentially affected as they sit in traffic backed up for an hour or better waiting for things to be cleared from the roadway. There's been traffic studies for several years that prove traffic accidents and fatalities rise when the cautious and slow drivers impede the flow of traffic. Sure if only everyone would slow down 15mph then the risks would be less but we live in the real world. On a 2 lane freeway where there is constant traffic, it's less dangerous for everyone involved to go with the flow.

 

[Brokedownbutgood]

What?



For a 30 mile drive 65-80 is a difference of a about 6 minutes. And yeah 6 minutes isn't a ton. For me that difference would waste about a half hour per day. Some days a little less, on my long days, it would cost me an extra 1.5hrs. Admittedly, I could shave 5 minutes here and there and probably make it up elsewhere in life I'm sure.

But flow of traffic again is the concern here. One person deciding to do 15mph less than everyone else can cause accidents. And it's not always the turtle that's involved. It's the guy doing 90 hitting the guy doing 75 in the fast lane trying to pass the guy doing 15 under. Then an innumerable amount of people potentially affected as they sit in traffic backed up for an hour or better waiting for things to be cleared from the roadway. There's been traffic studies for several years that prove traffic accidents and fatalities rise when the cautious and slow drivers impede the flow of traffic. Sure if only everyone would slow down 15mph then the risks would be less but we live in the real world. On a 2 lane freeway where there is constant traffic, it's less dangerous for everyone involved to go with the flow.

The guy doing 90 is the problem and not one that should make everyone else follow his stupidity. One should do the posted speed limit +-5 mph any more than thats a problem, any less well that nots usually an issue.

 

[jg08]

Last road trip my wife and I took from Prince George, BC to Victoria, BC and back.. Empty of course...

 

[Dieselfever]

Here is the 30 plus mpg formula.

• Tune helps, but not necessary.
• Stock SRAs or something equivalent. Inflate to 40-42 cold.
• Never let your RPM go over 2000 while shifting and 1700 while locked up in 8th.
• Never, ever go above 70mph, 65mpg is better. At 55mph and 1350 rpm you can expect your best mpg.
• Inflate right foot with helium. The lighter your foot, the better your mpg. Light right foot yields better results than all the above techniques.

Most find some or all of the above techniques intolerable and that is why they do not achieve 30mpg.

 

[bpdougd]

Here is the 30 plus mpg formula.

• Tune helps, but not necessary.
• Stock SRAs or something equivalent. Inflate to 40-42 cold.
• Never let your RPM go over 2000 while shifting and 1700 while locked up in 8th.
• Never, ever go above 70mph, 65mpg is better. At 55mph and 1350 rpm you can expect your best mpg.
• Inflate right foot with helium. The lighter your foot, the better your mpg. Light right foot yields better results than all the above techniques.

Most find some or all of the above techniques intolerable and that is why they do not achieve 30mpg.

^ This.....

Two factors overwhelm all others in determining fuel mileage: driving habits and tires. Other things can make small but measurable differences including winter blend fuel and terrain. I am also convinced (but cannot prove) that there are measurable differences between identically spec'd trucks. In other words, there is sample variation.

My 2015 Bighorn with 3.55's and stock tires got its best ever mileage during its first year on a vacation to Yellowstone. One tank was 30.4 and another was 32.2. After I replaced the stock SRA's with BFG KO2's my best-case highway-only mileage dropped to the 28-29 range. The truck has 50k on it now and that change from 30-ish to 28-ish has remained consistent over the intervening years so I conclude that the 2-3 mpg hit is 100% tires.

 

[John Jensen]

Since new and now at 19,526 miles my avg hand calculated is 19.58 mpg.
I have 10 ply 33"x17" AT tires, no air dam, leveled, a Leer shell, front grille guard. All items that reduce mpg performance.
I have used GDE or SFT tunes since the 4724 miles mark.
I am a short trip user as this is my daily driver (that's why the tunes, to turn off EGR).
My average fillup is 16.6 gals and includes 75% local (under 15 mile round trips) and 30% freeway driving.
The total avg mpg includes four 2000 mile roundtrips of 100% freeway/highway. Driving at 70-80 mph (usually at or 5mph over the posted). These trips average 22.77 mpg.

 

[MAS]

^ This.....

Two factors overwhelm all others in determining fuel mileage: driving habits and tires. Other things can make small but measurable differences including winter blend fuel and terrain. I am also convinced (but cannot prove) that there are measurable differences between identically spec'd trucks. In other words, there is sample variation.

My 2015 Bighorn with 3.55's and stock tires got its best ever mileage during its first year on a vacation to Yellowstone. One tank was 30.4 and another was 32.2. After I replaced the stock SRA's with BFG KO2's my best-case highway-only mileage dropped to the 28-29 range. The truck has 50k on it now and that change from 30-ish to 28-ish has remained consistent over the intervening years so I conclude that the 2-3 mpg hit is 100% tires.

I really don't think tires make that big a difference. I got the same mileage with the P-SRA's as I do a set of same size Load range E Cooper all terrains. I filled up yesterday on the way home, 100% my normal commuting tank 497 miles, 17.38 gallons of diesel and 28.59 mpg, smack dab in the middle of the same 27-29 I have been getting for 83,000 miles.

 

[timmytime]

...I'm not saying my mileage is bad. Just that it isn't what everyone says. For any truck, north of 20mpg is pretty good. And I don't only drive 75mph. But I drive the speed limit or pretty close with the flow of traffic. If the speed limit is 75mph traffic is generally flowing between 75-85mph. It is hazardous to be the guy doing 65mph in that clogging everything up.

Who said anything about going slower than the flow of traffic. I just don't drive roads where you have to go 75-85 to avoid "clogging everything up." I often drive a 230 mile trip from my house to my cabin, and I have a choice of multiple roads/freeways/highways to get there. I don't take the roads that have the 70 mph speed limit, I take the roads where the speed limit <= 55 mph.
So, here's why my mileage is (considerably) better than yours: I don't go above 55 mph, EVER. l also routinely get 30+ mpg. Its nice to be past the point in my life where I have to hurry all the time.

 

[John Jensen]

I really don't think tires make that big a difference. I got the same mileage with the P-SRA's as I do a set of same size Load range E Cooper all terrains. I filled up yesterday on the way home, 100% my normal commuting tank 497 miles, 17.38 gallons of diesel and 28.59 mpg, smack dab in the middle of the same 27-29 I have been getting for 83,000 miles.

It's a known fact that it takes more power to turn a 60lb tire that a 40lb tire.
You are fortunate that the physics law didn't result in a mpg change.
In my case it was a 1-2 mpg hit.