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Gasser fuel economy

hutchman

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Just got back from the gas station after 300 miles or so yesterday. I'm guessing about 20% around town and the rest interstate at 70 mph. This tank was 14.9 hand calc'd and the first was 15 even. That's about 1 mpg better than my last 2500 with a 392 and 3.73s. And about 1.5 mpg better than my Power Wagon.

With only 700 miles on this one, I'm cautiously optimystic. I'm hoping for another .5 - 1 mpg after this thing gets loosened up. We'll see....
 

Gondul

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Just got back from the gas station after 300 miles or so yesterday. I'm guessing about 20% around town and the rest interstate at 70 mph. This tank was 14.9 hand calc'd and the first was 15 even. That's about 1 mpg better than my last 2500 with a 392 and 3.73s. And about 1.5 mpg better than my Power Wagon.

With only 700 miles on this one, I'm cautiously optimystic. I'm hoping for another .5 - 1 mpg after this thing gets loosened up. We'll see....

That doesn't sound shabby at all...
 

hutchman

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Interesting fuel economy day. We started out in La Grande, OR and drove to Snowville, UT. It is almost exactly 400 miles with speed limits varying from 65 to 80. I drove the speed limit as indicated. It is 80 from the west to the southeast of Idaho except in the Boise area and construction zones.

As an interesting sidelight, the low fuel warning light illuminated just as we hit the exit ramp at Snowville, so this tank is a good example of how much is left when the low fuel light comes on. The truck took 27 gallons on the nose at Snowville which means there should be 6 gallons of fuel left in the tank when the light comes on.......assuming the truck has a 33 gal tank, which I think is correct.

That tank, with quite a bit of driving in the mountains/hills, and 70 - 80 mph most of the time, netted 14.9 MPG hand calc'd.

Now when I fill the tank, I do it much like the TFL guys do it....I fill it until it clicks, wait 30 seconds or so, and squeeze it again until it clicks. I do this at least twice. I filled it that way in Showville.

We pulled in for the night in south Provo and I filled the truck to be ready for morning. I filled it the same as always except this time after I clicked it the second time, I let it dribble in to ensure a very full tank. The driving for this fillup was straight onto the highway at Snowville, up the pass, and then down into the Salt Lake Valley. From the top of the pass out of Snowvill it was mostly a gentle down slope or level at 70 mph. After filling this tank the same way I always do, I got an astounding 18.6 mpg.

At first I thought I might have short filled it some way, but after thinking about it I did not.....it was full. The only explanation is the gentle downhill and mostly steady, very lightly loaded 70 mph through SLC. Traffic was moving steadily and without stop. IT was an unusual day for traffic in SLC.

in no way do I think this tank will be representative of what this truck will do normally, but it is an indication of what it might be capable of if you need to extend your range, the topography is right, and you slow down.

All in all, it was a very interesting day in learning how this truck does on the road.
 

hutchman

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Things chwnged for us today. We have a family emergency in IL, so we headed east from Provo, UT. The driving today was a mix of speed from 50 in Denver to 80 in Utah. It was mostly 75 on the interstate, however, we did cross the Rockies on I70. We pulled 5he hill on the west side all the way to 11000 feet and the Eisenhower Tunnel. We filled up teice today.....once on the western slope @15.6 mpg and tonight in Colby, KS @ 16.8.

Again these are hand calc'd and not from the lie-o-meter. However, it is somewhat accurate. Usually within .5 mpg or so.

So after 2000 miles, the average is going up. It is now 1.5 mpg better than my last gas truck with 3.73s and a 392. I'm liking the way this one is headed!
 

Stumblefoot

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Hutchman, I know your route like the back of my hand. Are you pulling a heavy trailer to Illinois? I'm curious to read your climbing feedback on your gasser. How was the climb up;
  1. Vail Pass (it starts after the big right hand turn east of town all the way up to the rest area); and
  2. Eisenhower Tunnel (from Silverthorne at the base)?
 

hutchman

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I am not towing, but while the pull is fresh in my mind, let me tell you a story.

I spend a lot of time watching TFL videos. I like the way they document stuff and I know tne 392 has had a somewhat checkered past on the Ike Gauntlet. I was very interested in just running that route and also seeing how the truck would do.

Today is Sunday and 70 East was full of the "I'm done skiing for the weekend so get out of my way" crowd on the way home to Denver. It would not have been a good day to try to run the "Ike" but it was a good day to test an unloaded truck in traffic on a 7% grade.

The pull up the Vail Pass was without issue. Seems to me I had the truck in CC and it just pulled it with no issue.

The Ike was very different.... It was slow, but moving most of the time. near the top, it slowed to a crawl and stopped. What I noticed in the stop/slow/go traffic was it took more throttle to accelerate in a normal fashion. There was no issue, but it did take more. However, I was really watching to see if there was going to be a noticeable effect from altitude......and there was. But someone not paying attention might not notice it.

Was thdre power loss? Yes there was. Was is serious? Not to me. Would I tow a 13,000# trailer up there? Yes I would. It will not tow like a diesel, but I would tow at it's limits and not worry about it. The 8 speed makes this a much better truck I think.
 

Stumblefoot

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Thank you for sharing the story Hutchman. Exactly what I was looking for.

If you pulled up Vail Pass cleanly, the same would have most likely happened on the climb to Ike had it not been a Sunday afternoon during ski season. BTW... I-70 to/from Denver/Frisco is the only rural interstate in America that has traffic congestion on weekends. We've lived here 2 decades and our department of transportation HAS YET to come up with a solution to solve it. In fact, the brilliant minds at CDOT literally just released a press-release last week recommending the primary solution as car pooling to the traveling public. Yup! That's right. What we've all been doing for years around here and they still think it's not only a viable solution, but the primary one. Knuckleheads! But alas, I digress. :)
 

hutchman

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I would love to hook to a trailer and pull tne Ike. I really get a kick out of the TFL guys! They are living the dream!

And let me make 1 point again......I think the transmission makes this truck what it is.
 

hutchman

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Now back in the Midwest and averaging 15.2 mpg after about 3500 miles. My old Bighorn with a 392 averaged 13.9 over 15000 miles. This new truck is "da bomb!"
 

CrazyHorse

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Just logged in for the first time looking for some feedback. Thanks for all the comments and discussion. I currently have a 1500 Ecodiesel and tow a 28ft MPG trailer. A bit close to max (~500 lbs) and it doesn't feel good in arid areas with 10+ mph winds. Went and test drove a 2018 2500 diesel last night because they didn't have a 2019 6.4 Hemi 2500. Really liked the diesel, but think it would be too much truck considering I only tow once a month (not to mention the price difference between Diesel and Gas 2500's). Dealer is looking for a 2019 with the 6.4 Hemi. This forum definitely helps. Let's see how things go. Even though I know I'll miss the economy of the 1500 ecodiesel, I loved how the 2500 felt on the road.
 

Gondul

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Welcome @CrazyHorse!

I decided on the 6.4 because I really don't tow often enough, or heavy enough, to really justify the 6.7.
Additionally, the payload on a 2500 with a 6.7 isn't much better than that on a 1500 so you really need to go up to a 3500... my 2 cents of course.
 

orlando bull

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Welcome @CrazyHorse!

I decided on the 6.4 because I really don't tow often enough, or heavy enough, to really justify the 6.7.
Additionally, the payload on a 2500 with a 6.7 isn't much better than that on a 1500 so you really need to go up to a 3500... my 2 cents of course.
I fully agree with this... I did go 3500 diesel, and, my reasons are below;

  1. I wanted it. The rest are likely justifications to support my desire for it.
  2. We have a 7500# travel trailer now, didn't feel good behind the f150. We have discussed upgrading to a larger fifth wheel at some point. While I could get the payload, I have read that less than 10-11,000# is gasser territory, greater than 15,000# is diesel, and in between is really a gray area where gasser may do it, but, with noticeable power restrictions.
  3. Resale - wife and I have twins on the way to add to our 3-y/o... so, I am going to be keeping this truck for quite a while. It's more money now, but, when I think about getting rid of it with higher mileage, the diesel should still have really good value.

The big things for me were "want" and possible upgrade of our RV. I bought my f150 2 years ago before we had an RV, that wasn't totally in the plan, so, I didn't think about needing something bigger. I didn't want to get in the same situation buying enough to do what I want today, but, having it bite me again in the future if we want to upgrade. If you don't think you'll go bigger on your camper, the gasser should be great for you. You'll definitely feel it in your fuel mileage, but, you can buy a lot of gas for $9,100.

I actually think RAM could do really well with an HD ecodiesel for weekend warrior RVers. Something with 330hp and 450 ft-lbs of torque, maybe a 12-15000# tow rating, that is capable of getting decent mileage both towing and not. If that was available in a 2500, I would probably really consider it. You'd get the suspension upgrades of an HD truck, but, wouldn't have to sacrifice the mileage of a half ton. The current eco wouldn't work, they would have to develop a larger engine to increase towing capacity and give more HP for moving a heavier truck off the line.
 

DevilDodge

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@CrazyHorse. You have an ecodiesel which gets good mileage, but you do not feel comfortable with the 1500.

The 6.4l isnt going to get near the mileage...but it is a true Heavy Duty engine. It goes through the same durability tests as the Cummins.

The new 8speed allows this engine to be in its power band much better.

What exactly are your weights on your trailers?

I know, people love their diesels, but if you are not towing regularly, at weights over 15000 lbs, high elevations, regularly over 70 mph(note that some states only allow towing at 55mph) and/or long distances...the 6.4l will be a great match.

As @Gondul said. The diesel drops payload...and also a bumper pull trailer on all HD trucks tops at 17000lbs.

So, if you do not need the rush of power or are not over any of the above situations...the 392 HEMI is a true workhorse too.
 

CrazyHorse

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Orlando bull,

It's a 28ft MPG at 7200 lbs. Of course that's empty. Once loaded up it gets near 8000 (7800). Then of course I put additional items in the bed of the truck. Bikes, dog, etc. My Ecodiesl is rated at 8700 which means I'm always close on weight limits (I also have a WDH which works well and the torsion is pretty tight). It pulls fine, but when I'm in areas with wind or under windy conditions, I think the natural lightness of the truck works to its detriment. My daughter felt nervous once when a blast from a semi hit us a couple of times. Naturally I keep things at or below 65.

Like I said, I love Diesel, but I just don't know how I would fair with a 6.7 Diesel 2500. Right now they're moving out the 2018 models to make room for the 2019's they have in the lot, so they're marking down the 18's to move.

Thanks all for the comments and information. It really helps.
 

Gondul

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I wracked my brain my brain for a good long bit before I finally decided... best of luck to you!
 

hutchman

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FWIW, I towed an 11000# 5th wheel with a Chevy 6.0 and 4.10 gears. It got 8 mpg towing and pulled fine. Not as good as a diesel, but it was OK. I pulled a 15000# 5th wheel with a Cummins 3500 SRW, and it got 9 mpg towing. It pulled that trailer without fuss. On a 6% grade, after slowing for a corner, it would accelerate right back up to 65 mph. A plus for it was a true 20 mpg empty on the highway.....and that was good.

This time I bought a gasser because I have no intention of towing anything over 12000# in the future and this new truck will work well for that.
 

CrazyHorse

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Yeah. Quick update. They don't have a 2019 2500 6.4 in stock but can get one in. There downside, at least for me..... They cannot offer the same incentives that they offer on the 2018s in their lot. The difference in price between a 2019 Laramie 6.4 gas vs a 2018 Laramie 6.7 diesel is ~1000. So while a diesel pulls more than what I need, a gas 2500 is almost the same price, of course this is because they are trying to get rid of their remaining 2018 models. I looked at fuelly and the diesels average 15 mpg on the site. Is there a downside I'm overlooking?
 

Gondul

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One biggie for me is that a 2500 with a 6.7 is not going to have much of a payload.
Also from what I understand, short trips are not the best for these new diesels due to the regen cycle.

@hutchman is getting 15.4 with his Tradesman 6.4, Laramie may be a little less due to weight of extra options.... maintenance costs are a wash. Even though they are more expensive for the 6.7, they are almost double the interval for the 6.4.
 

CrazyHorse

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Double the interval for the 6.4....... wow, I didn't know that. I guess it is a wash if that's the case. I have only my Lonestar ecodiesel to use as comparison. No issues with it in 78k miles. However, others have complained of issues. Not to mention the lawsuits coming up...... I will say that the oil pressure differences between an ecodiesel and a Cummins were significant. The ecodiesel moved up quite a bit until warm. The Cummins was steady all the time. I think that's the reason some folks have had engines blown. If it's cold and you turn it on and take off right away, that pressure is going to skyrocket. I don't know about the Cummins, but the eco uses 11 quarts of oil.
 
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