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4th Gen Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine, Transmission, etc...NO ADVERTISING

Thread: 6.7 L Fuel economy Reply to Thread
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  Topic Review (Newest First)
05-03-2019 07:02 PM
Jimmy N.
Quote:
Originally Posted by djom1cincy View Post
My rfe trans did this a month ago. I parked against a curb with my rear tires. When I got back in it was hard to pull out of park. I chalked that up like parking on a hill and not using the e break. Once on the road my trans was whining just like yours. It was speed related. Faster I went the loader it was. Best I can describe is it sounded like a Chevy blazer from the 90s if you know how they sounded. After a couple stops at stores it quit and hasnít done it since.
Thanks! I can only hope that this tranny also self heals. Apparently there's an update (21-0719), that could help, but for that it'd have to go to a dealer and I don't like that thought.

Even tried frying the shifter interlock today, since supposedly three minutes in Park and with the brake applied will cook it, and allow shifting out of Park without pushing the brake.
No such luck, and I really don't want a dealer to do that recall.

Anyway, it was fairly level where I stopped for fuel, but that doesn't mean the same thing that happened to you didn't screw mine up, too.
Never did stop again until back home. Guess it'll be worth hooking up a trailer and hit the hills and find out.
05-03-2019 06:52 PM
N of 60
Quote:
Originally Posted by Minnow101 View Post
And that would what in miles and gallons ?
US or imperial?

https://www.calculateme.com/gas-mile...0-km-to-us-mpg
05-03-2019 06:39 PM
djom1cincy
Quote:
Originally Posted by Jimmy N. View Post
Oh, I did fill the little 22-gallon, it was the 52 that I didn't realize was at only 3/4 when it clicked off.



Needless to say, when the whine started my first thought was "Uh, oh, there goes the diff". With the trailer in tow, and not expecting to make it home before midnight without any problems, it didn't look promising.



Then I noticed that the whine was rpm, not speed related, which naturally changed everything. Trans ran between 161 and 163 degrees even on long and somewhat steep grades, so it sure wasn't a heat issue.



I need to see if it has thrown any codes, and found out that there's some update as of March 22 about communication with the speed sensor. That could explain the odd shifting, but (in my mind) not the whine.



By the way, it was indeed a good trip, but not exactly uneventful. Far from it. But that's a different story, or three.


My rfe trans did this a month ago. I parked against a curb with my rear tires. When I got back in it was hard to pull out of park. I chalked that up like parking on a hill and not using the e break. Once on the road my trans was whining just like yours. It was speed related. Faster I went the loader it was. Best I can describe is it sounded like a Chevy blazer from the 90s if you know how they sounded. After a couple stops at stores it quit and hasnít done it since.


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05-03-2019 06:26 PM
Minnow101 And that would what in miles and gallons ?
05-03-2019 06:20 PM
BrianF I just did some hand calcs the other day. Over a 311 km span, most was highway, got 14.5L/100km. That's unloaded and max 112km/h.

Did another 300km run and averaged 15.5L/100km. Kept speeds at or below that 110km/h mark.

My guess is that we are still getting winter blend at the pumps but will need to verify.
05-03-2019 03:58 PM
TripitakaBC
Quote:
Originally Posted by N of 60 View Post
Exactly, thats my point. 26 ltrs per hundred KM is more believable.
I'd be selling it way before I got to that point. As Fuelly shows, my average over the last 3 years is 17.2L/100Km and that is with a lot of heavy hauling. That toyhauler in the photo is right around 10,000lb loaded and most of those fuel logs are with that on the back. There are still folks that tell me it's impossible and my response to them is 'for you, maybe." It doesn't matter whether folks want to or choose to believe it, the evidence is right there. My Google timeline for mid-2016 to mid-2018 is a hoot, some folks tell that's BS too. At the end of the day, none of it matters a damn.

What I will add is that I saw a noticeable difference in fuel economy after I switched from the low-tread Toyo M-55s that were on it when I got it to the cheaper Cooper Discovery. Those Coopers suck, horrible wear rate and it shaved a fair bit off the economy. It will be interesting to see if that comes back when I go back to the M-55s but as the Coopers have got to the wear indicators, it hasn't really come back to the previous levels. I can't get away with a standard road pattern, I need E-rated so there are limits to what I can squeeze out there. Putting the canopy on it made a hell of a difference too, I don't just recall what I worked the figure out to but it was more than .75L/100Km.
05-03-2019 03:31 PM
N of 60
Quote:
Originally Posted by TripitakaBC View Post
No, that would be worse, not better. '
Exactly, thats my point. 26 ltrs per hundred KM is more believable.
05-03-2019 03:22 PM
TripitakaBC
Quote:
Originally Posted by N of 60 View Post
26 MPG with a 3500 DRW? You mean 26 ltrs per 100KM or you have never driven back up that hill you have been coasting down yet.
No, that would be worse, not better. Flat ground driving, no traffic, 50mph, 10% in the tank, no payload, no towing and full deletes with economy tune, I can get the lie-o-meter down to 8.1L/100Km which we know is BS but I've got enough km on that thing to know what my correction factor is.

I'm not saying I'd get that over a full tank but trip-to-trip it's in that 25-26. I *am* that guy everyone hates to get stuck behind. :-) I've had the 'That's BS!' comments before and often but how many other folks do you know that have 100K+ Km tracked on Fuelly? I'm all over that stuff, especially with the price of fuel up here.

All stems back to my old man giving me one piece of advice when I started to drive; 'if you want to make the most of your gas money, imagine your balls are between your foot and the gas pedal.'
05-03-2019 03:10 PM
N of 60
Quote:
Originally Posted by TripitakaBC View Post
I've tracked over 100,000km on mine on fuelly.com with nearly 90,000Km of that pulling my 10,000lb toyhauler. Average has been 17L/100km or 13.7mpg but driven carefully with no towing, I can regularly get 26-ish mpg.

Yes, I do drive it like your grandpa. :-)
26 MPG with a 3500 DRW? You mean 26 ltrs per 100KM or you have never driven back up that hill you have been coasting down yet.
05-03-2019 02:02 PM
FlaCracker I am averaging 19.6 mpg, city/hwy on my truck, daily driving, running 150HP GDP tune deleted...love it. Before I deleted, did a 1,200 miles trip to NC, delivering a 98 Ram truck, total weight around 9k, averaged 12.9 mpg.
05-03-2019 01:13 PM
TripitakaBC I've tracked over 100,000km on mine on fuelly.com with nearly 90,000Km of that pulling my 10,000lb toyhauler. Average has been 17L/100km or 13.7mpg but driven carefully with no towing, I can regularly get 26-ish mpg.

Yes, I do drive it like your grandpa. :-)
05-03-2019 01:08 PM
Jimmy N. Oh, I did fill the little 22-gallon, it was the 52 that I didn't realize was at only 3/4 when it clicked off.

Needless to say, when the whine started my first thought was "Uh, oh, there goes the diff". With the trailer in tow, and not expecting to make it home before midnight without any problems, it didn't look promising.

Then I noticed that the whine was rpm, not speed related, which naturally changed everything. Trans ran between 161 and 163 degrees even on long and somewhat steep grades, so it sure wasn't a heat issue.

I need to see if it has thrown any codes, and found out that there's some update as of March 22 about communication with the speed sensor. That could explain the odd shifting, but (in my mind) not the whine.

By the way, it was indeed a good trip, but not exactly uneventful. Far from it. But that's a different story, or three.
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