Fuel Milage Sucks

[Older Slower Wiser]

I have a 2015 Ram 1500 ecodiesel with 34,000 miles. 1.55 gear ratio and full size topper. 90 percent of my driving is interstate and about 25 percent of that is pulling a 3,000 lb trailer. I have never once gotten over 21 mpg. Usually average 18 to 19 mpg with out trailer and 12 - 14 with trailer. After having topper installed mileage dropped about 1 mpg to the current 18 - 19 mpg. Never had a code or any other problems. Generally drive 75 - 78 mph.
Anyone have any idea what might be going on? I've bought fuel in at least 10 different states so know fuel isn't the problem. Hope this is not a cam timing gear slip issue.

 

[tomcatsr]

MIght be. I have about 36,000 miles and using cruise at 65-70 on southern Missouri interstate I got about 34.3 mpg from southern part of state to St. Louis and back. That's the dash mileage so I don't know how accurate it is. My biggest everyday problem is all the idling I do during a normal day around the farm. Locally I only average about 16-17 because of the idling which beats my old Chevy 2500 with the 6.0 all to heck!

 

[R Stanley]

Might try and slow down to 70 and see if that helps any, after about 73 my milage will start to decline some,

 

[Brokedownbutgood]

Slow down and stop using cruise control. Also when is the last time you changed your fuel filter, air filter, etc?

 

[Older Slower Wiser]

Best Milage I got was 200 miles round trip average about 60 mph - fuel milage a whopping 21 mpg. Older fuel and oil filters, filter better than new. So I do not change at most recommended time intervals. There is a tipping point though, you don't want a filter to plug and bypass. I do pay more attention to filters than most. Also part of my job.

 

[EcoJohn]

I have a 2015 Outdoorsman with the ECO (27,000 miles ). During the summer the best HWY mileage I seen was 28 mpg. My normal day to day driving (which is some Hwy) is 24-25 MPG. HOWEVER now that winter is here in Wisconsin I am seeing 20-21 MPG day to day driving. I also don't idle to much. Towing a 2000lbs load I see 17-18 MPG in the summer.
Does anyone know if there is anything you can do to boost winter mileage??

 

[R Stanley]

I do not have the GDE tune yet, going to get it sooner than later, studying the idea now. but hear on here and other places and on their Web site it will add a couple of miles per gallon. A thought.

 

[harry]

I do not have the GDE tune yet, going to get it sooner than later, studying the idea now. but hear on here and other places and on their Web site it will add a couple of miles per gallon. A thought.

what is your mileage now and what is gde

 

[BoostN]

what is your mileage now and what is gde

GDE is a company that provides tuning for the EcoDiesel engine, and other platforms as well.

 

[R Stanley]

My milage around town, 21/23, on open road 2 lane 27/28, freeway driving 25 to 28 depends on speed and elevation of the road, between Little Rock and Oklahoma 27/ 28, between Memphis and Birmingham 25 to 27. Anything over 73 MPH my milage will start declining. Also depends how aggressive I drive it to.

 

[Older Slower Wiser]

Drove from Illinois to Shreveport Louisiana and Illinois to Muskogee Oklahoma pulling bass boat. 13.5 mpg best I could get coming or going on both trips. Had a Toyota Tundra that saw one trip to Muskogee and got about 12 mpg. Really miss that truck.
First trip after getting ED was to Table Rock Lake Missouri - after trip complained to dealership about milage - was told it needed to be broken in. It's broke in now - no difference in mileage. No codes, No smoke, about 1,000 mpg on urea.
Just the fact Milage is bad should pull a code. But there are none.

 

[flying7]

wish I had better answers but it seems like you are one of the few with fuel mileage problems. Most of us do really well.

 

[aldwayne]

I have no issues with the fuel mileage also. I do mixed driving and highway.

 

[Radio_Flyer]

Something is up for you to have that bad of MPGs. I commute in the DC area traffic and using fuelly for all my fill-ups I am averaging just over 24mpg. When the traffic isn't as bad my commute for the week averages mid to high 26s. I run 2-3 MPH over the speed limit when I can. On my trip to SC and back, Tenn and back. i'm getting right around 30. I have the 3.92 gears. Even though I said I wasn't going to, I went GDE. I have a trip to SC coming up, will be interested to see how it goes. I know we are still on winter fuel, but it should be interesting.

 

[DMDK-ECO]

I run GDE for the past 6months and I average 11-12L/100KM which is 24MPG AVG and that's 95% city driving at Sealevel.
Mind you I do not drive easy, I like for the truck to be responsive and go, so no feathering on my part.
A month Ago I towed a 3000lbs trailer for 500KM through the Rockies and Averaged 14.5L/100km all the way in Auto 4X4 mode with frequent engagement of 4X4.

Something in your situation doesn't make sense, did you do a hand calculation at the pumps, disregarding the comp read?

 

[DMDK-ECO]

Oh eah and I run 285 BFG KO2's with Rear Airbags at 15PSI

 

[Bobby Lara]

I have a 2015 Ram 1500 ecodiesel with 34,000 miles. 1.55 gear ratio and full size topper. 90 percent of my driving is interstate and about 25 percent of that is pulling a 3,000 lb trailer. I have never once gotten over 21 mpg. Usually average 18 to 19 mpg with out trailer and 12 - 14 with trailer. After having topper installed mileage dropped about 1 mpg to the current 18 - 19 mpg. Never had a code or any other problems. Generally drive 75 - 78 mph.
Anyone have any idea what might be going on? I've bought fuel in at least 10 different states so know fuel isn't the problem. Hope this is not a cam timing gear slip issue.

Im only getting 20mpg actual, my computer averages 21mpg and the active reading is 21 to 30mpg...i drive 73 on hwy. In the city i lead foot, Haha. Its hard to find non mixed bio fuel in oregon, i think the previous owner put bio fuel in my rig and that is bad stuff to use.

 

[Brokedownbutgood]

 

[Bobby Lara]

Great info, thanks

 

[AquaGator]

I recently purchased a used 2014 Ram 1500 Big Horn crew with Eco-diesel with 48k
miles and have also been getting "bad" mileage. I have logged a couple thousand miles and the best I have done is 24 mpg at 72-75 mph on the highway. Towing 3500 lb trailer I average 16/19 city/hwy. I don't use cruise control, I live in central Missouri so lots of hills, but all of my reading on this site and others implies that I should expect better. Before this truck I had an '05 ram 1500 with a 4.7 V8. It got about 14/17 city/hwy mpg and 10-12 mpg towing so I am happy with my new trucks numbers in comparison, but hoping for some insight. I took it to the dealer and they said there is nothing wrong with it and I just need to learn to drive a diesel, which was a little insulting because I also own a 2013 VW Jetta TDI and get well above estimated city/hwy mpg. Any suggestions?