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Towed my toy hauler from south of Tampa to Maggie Valley, North Carolina. Great week to ride motorcycle in the mountains but this is about towing. Here's the truck and the toy hauler with one of my Harleys under the awning one evening. My close guess is the rig weighed about 6,200 as loaded.

Power was fine. Ran in tow-haul mode but the transmission shifting was still obnoxious. To run 68 mph on I 75 this darn thing often shifted down into 5th gear and ran 3,200 rpm. Mostly it would run in 7th at 2,200 rpm. I am used to my Cummins in manual 6th gear. This thing has little torque compared to the Cummins and I do not like the automatic with all the shifting.

Did run up some 7% mountain grades and held about 55 mph. No issues but that's it. Downhill I manually shifted the thing down to help hold it back. That does work but can run the rpm's up into the 4,000 range. I see no fuel flow during that time.

Used a quart of oil getting there but then that oil consumption stopped. Truck now had just over 6,500 miles on it and that is the original oil that I will now change.

Pulling on the interstate I think the fuel mileage is awful and no better than my old Cummins. Look.


Low 12's. I mean that's it. Real disappointing to me. That's a picture typical of towing rather flat interstate around 68 mph. I did show times when it whent up to 15 but that was much slower running around Atlanta and on two-lane roads going 55-60. It did around mid-13's in the mountains running up and down some steep stuff.

I did a lot of hand-calculating on fills and mostly my calculations were LOWER than what the EVIC showed. Not always and my impressions there are the EVIC is a bit optimistic while towing.

Overall the trip was in the higher 12's for mpg. My take is a couple tenths less than this showed when I got back.



There were times
 

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interesting I would have guessed and hoped for more. heading out from North Carolina to California in a couple months with our travel trailer (~5200lbs). I am ok with going 60mph if it helps as we are in no rush but hope to get at least 15mpg
 

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Discussion Starter #3
Slowing down will help a lot. Fronts of travel trailers are not like towing a boat or some equipment trailers. Wind resistance is a big deal and that exponentially increases with speed. You should have a satisfying tow.

Also. Thanks for the reply. When no one responded I questioned whether the post was worth the effort. AMAZES me how many read posts and then do not make any kind of effort to at least thank the poster for the time and effort involved.
 

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Nice report, and good looking truck. Too bad the towing mileage is not what you thought it would be. I think the real benefit to this engine is when you are NOT towing. For me that is the vast majority of the time. I can have a daily driver that gets as good or better mileage than my jetta, but is still capable of doing some work on the weekend when it's time to play.
 
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Nice report, and good looking truck. Too bad the towing mileage is not what you thought it would be. I think the real benefit to this engine is when you are NOT towing. For me that is the vast majority of the time. I can have a daily driver that gets as good or better mileage than my jetta, but is still capable of doing some work on the weekend when it's time to play.
highway mileage for the win :D
 

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Since I have a utility trailer connected 80% of the time and I have a travel trailer mpg was the selling point for me while towing. I am consistently getting about 18.5 mpg average tank with towing my ~3500 lb enclosed 14ft trailer and a mix of city/ hwy without it for 100 miles or so of the tank. I am happy with that as my old rig was about 12.5 with the same combo. I have not done the travel trailer yet but my old rig was about 9-10mpg at 60mph so if I can get at least 15 that will be a win for me. I don't do Fuelly as it would not represent the truck well since it can't specify how much of that is towing
 

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Well the higher the payload the more the engine is going to work and your hitting the higher end of a 1500s payload (depending on features). So at max 9,200LB your at 67% of its tow capacity and a 2500 would be at 38% with its 16,200 capacity. So if you want to compare apples to apples load up a 2500 to 67% of its capacity and report back its gas mileage.

I find it impressive that at 67% loaded it runs similar to the 2500 at 38% loaded.
 

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10% thanks for the reality check...

I know that I have stated in the past not to expect any better mileage towing a travel trailer.

You cannot expect to obtain higher fuel mileages for the same size trailer. The wind loads are the same, the mass-inertia of the trailer is the same and the work performed in pulling is the nearly the same. So the fuel consumption (energy) is expected to be nearly the same that is used to accelerate and keep at constant velocity. I would expect to see about 12 -14 mpg towing our 25' Airstream (7800 gross). This is what I get on my 6.7, and would not expect any better on our ED.

Of course there is a huge decline in mileage as you go faster:
55 to 65 increase of 40% wind resistance.
65 to 70 - 16%
65 to 75 - 33%
55 to 70 - 62%
 

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Since I have a utility trailer connected 80% of the time and I have a travel trailer mpg was the selling point for me while towing. I am consistently getting about 18.5 mpg average tank with towing my ~3500 lb enclosed 14ft trailer and a mix of city/ hwy without it for 100 miles or so of the tank. I am happy with that as my old rig was about 12.5 with the same combo. I have not done the travel trailer yet but my old rig was about 9-10mpg at 60mph so if I can get at least 15 that will be a win for me. I don't do Fuelly as it would not represent the truck well since it can't specify how much of that is towing
speed, size and drafting of your trailer would effect towing mileage. What is your mileage at typical highway speeds of at least 65mph? Does 18.5 still hold?
 

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speed, size and drafting of your trailer would effect towing mileage. What is your mileage at typical highway speeds of at least 65mph? Does 18.5 still hold?
i rarely go above 55 on our narrow 2 lane rural hwys. However I do manage one property that I get on a 70 mph speed limit hwy for about 10 miles each way. When it is flat and not windy I get about 20-21 mpg but there are a lot of small up and down hills so I see it go to about 11-12 up and almost 30 down. BTW I keep tow mode off at that speed so it will go into 8th gear
 

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Discussion Starter #11
As an aside I also have and tow a small open trailer. Twice I have had 800 lb motorcycles on it and towed. Each time this Ecodiesel still got over 20 mpg towing at my highway speeds. No wind resistance.
 

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how much you guys think a towing wing could be good for? I've heard some companies claim as much as 10% gains, but IRL I'm not sure...
 

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how much you guys think a towing wing could be good for? I've heard some companies claim as much as 10% gains, but IRL I'm not sure...

I don't know. It's hard to say without some real world testing of different sized trailers.

Now If I were to postulate...I would say for taller trailers, the wings probably are effective in reducing frontal surface parasitic drag. However, you still have drag from the sides, bottom, and rear surfaces. I also have reason to believe that the wing may cause rear suction to increase as a result of increased airflow over the top, but, the net difference with front would still put you in the green.
 

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Discussion Starter #15
The back of my trailer is a flat box. Same with my truck that has the cap on it. Both would have a "suction" /vacuum issue that should hold things back.

Another good point.
 
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