Fuel Milage

[SCummings]

I towed my 7000 lb travel trailer with my 2001 Quad cab 4x4 last weekend. I went from the bay area up tp Mt. Shasta, Ca. I only averaged 9. 5 mpg. The truck has 3000 miles on it. Should I suspect the milage will go up considerably after it has more miles on it, or does something not seem right.

 

[Archive]

When I tow, I get all kinds of different mileages. Depends on a lot of factors... aerodynamics of what is being towed, wind, weight, how fast you drive, etc.



I just hauled some hay last weekend and was down to 10mpg, last time I got almost 14mpg.



I would think after you get some more miles on your Ram, it will improve. And hauling that trailer around will quicken the process.

 

[TKilgore]

Mileage

I have towed my 30' Nomad from the start with my 2001 3500 3. 55 4x4 and have gotten 11 to 12 mostly interstate 70 to 75 mph. I now have just over 10k on it and hasn't gotten any better yet but I think my IAT values are off (thats another thread lol)

Good Luck to you and tow often and tow hard



Tom

 

[Evan A. Beck]

I have seen a lot of trucks come through the shop, and the owners are complaining of low fuel mileage... Seems the main cause is boost leaks at all the intercooler connections. More often than not, there are casting ridges on the top and bottom of the round openings on the intercooler where the hoses connect. The result is the hose will not seal correctly, and boost will eak out, causing a lack of air to the engine. To fix it, simply remove the hoses, and file down any ridges you see. Do the same on the intake plenum too.



Low fuel pressure can cause low mpg as well... So get it checked!

 

[Doc Tinker]

My TT is about 7000#. The last time I towed using a borrowed VA, I got 14 mpg. I've got a Torque Dog (same as the Power Puck) now but I haven't been on a long enough trip to know what it does.



I average 12 mpg without the VA or Torque Dog.



My truck has the 3. 55 gears, if you have the 4. 10s you won't do as well.





Doc

 

[Archive]

Doc... I disagree with you. I have 4. 10s, and I think the towing speeds. loads, etc are the factors that are as important as rear-end gearing.



Cummins put out a bulletin a while back that states for 24 valve best economy, drive in the 1800-2000rpm range. For best towing, drive in the 2000-2200rpm range. If I have 4. 10s and drive at 1900rpm, I may very well get better mileage than you driving at 1500rpm.



These rpm ranges seem to work well for me... anybody else ever play with this?

 

[Doc Tinker]

Rob. . I have never towed at 1500 rpm. Seems that the speed that I travel usually keeps me up close to 2000. If I drove at those speeds with the 4. 10, I'd be out of the sweet-spot.



I think the 4. 10 will do better with larger loads, than the 3. 55 though.



Doc

 

[MidwestMotorman]

Economy

I found out that towing a load (about anything over 5000 lbs) that being at 55 mph put the rpms about 1500 with my five speed and 3. 55 gears. I found out the mileage is the same with the same load pulling in fourth at 2000.



I recently was on a long haul and tried playing around. The truck was much happier pulling at 2000 rpm. It also made for less shifts on the hills. I would be worried pulling a load at 1500rpm with a manual five speed as you may hammer off the overdrive nut when the engine lugs.



With 4. 10s that sweet spot would be right at 55 mph in fifth. I do a lot of non-towing driving and there were lots of times when I see speeds of 80-100 mph and those 3. 55s pay off then.



4. 10s would allow you to run those 35" tires and still have good rpm's for towing. To each his own...

 

[dewdo]

I tow the fiver at 2000 RPM which gives me about 62 mph and I get 11. 5 to 12 MPG. I get the same mileage with the camper on. Trailer weighs 15,000 lbs and the camper comes in around 4,000 lbs. I guess the wind resistance is the reason.



Dewdo in the other Washington

 

[RJ2]

Well this certainly falls in line with what I have been asking. My posts were under (Realistic MPG) and I got alot of I should be in the low 20's. Cummins told me on an auto 3500 the (15 to 17. 5 MPG) empty (13 loaded), range was realistic. Anything other than that was on a mileage contest with themselves.

 

[BRobertson]

Last month I towed a 24' enclosed vehicle hauler from Glenrock, Wyoming to Seatle Wash. . When I weighed in at the barge dock turns out I was at 26000+. I averaged 12. 5 mpg (actual, not trip computer) I have approx 19500miles on the truck now.

 

[SCummings]

Thanks

Thanks for all the input. I'll check the intercooler connections. I guess everybody who told me around 20 mpg was full of you know what. Thanks again.

 

[Doc Tinker]

That 20 mpg is possible in some empty trucks, not towing though, unless all your driving is down hill



Doc

 

[Fireman Dave]

I agree with Rob.

I agree with Rob. Aerodynamics/wind resistance are a big factor. When I towed my 27' TT to CA and back in June, I averaged 10. 5mpg for the whole trip. It varried at times between 8. 5 and 11. 5. Wind conditions played a big part too. My trailer weighs around 6,000 lbs. I don't think the weight was much of a factor. I think the wind conditions, wind resistance of the trailer, my speed, and the fact that I towed with OD off were the significant factors. I usually towed around 65 mph at about 2200-2300 RPMs. I would have picked up maybe a couple of mpgs if I'd have dropped my speed 10mph and towed in OD. BUT, then I would have been under 1800 RPMs, thus lugging it, in my opinion. Also, towing out of OD is better for the transmission.



So I don't think your mileage is abnormal. I usually get 17. 5-19 (and I hit 20 once) when not towing. My truck had 13k on it before my trip. 19k, now.

 

[MidwestMotorman]

Over twenty is possible...

Doc



Over twenty is possible. I towed a car on a car dolly (plus a 1000 lbs of tools and gear in the back, and four people and gear inside) through the hills of southern New York and averaged 24. 2 mpg. I never shut the truck off (had six hours of idling on the tank) and always filled the tank to the top. I drove at 50-55 mph the whole tank. This is going by actual distance driven and gallons used as I do not have a mileage computer. I used the cruise, have 3. 55 gears, towed in fifth gear, and had 21k miles on the truck. This was in wintertime. My truck is not bombed either. On the way out there without a car on, I averaged 21. 4 mph going 75-85 mph.



I keep track of my mileage in a book with figures, distance, and location so I can figure how my truck will handle on any future trips. Plus, if and when I ever sell the truck, the next owner can see proof and receipts for mileage expected out of the truck.

 

[AKDrifter]

My mileage has improved 2-3 mpg since day 1. I currently have 8200 on it and have towed 7500 miles of that. I'm a sure believer that you have to make it sweat hard to break it in right. 19-20 mpg unloaded, 12-15 loaded up.

 

[George D]

I have 3500 miles and am getting 16 to 16. 5 around town (not many traffic lights). Towing when brand new averaged just over 9 mpg at 62-63 mph. I am towing a fiver that puts me well over GCWR but it handles it with no problem. Will be doing about 10-12K miles this winter and am hoing for a little improvement.

 

[Gunny]

SCummings, I also pull my trailer from the Bay-Area up to Redding. my new truck also has about 3500 miles on it and I have not as yet pulled the 5er (12,000 lbs) up there. However my old truck 98 12valve Auto really struggled with this pull. I would tow up I-80 to 505 and then over to I-5 and then North to Redding. My mileage was never better than 10 and that was on a good day. My new truck is an H. O. 6speed and I am doing much better with it about 15. 5 to 16 unloaded and 11 to 13 pulling the trailer. I think that as these trucks get a little mileage on them they will do better. Good Luck Gunny

 

[brobeson]

True MPG

IMHO MPG is a per truck, per driver, per situation thing.



If you compute your MPG over enough tanks, you will find the average of what you and your truck can get.



I have logged every drop of fuel that has gone into my truck.



The 1st tank of fuel (running empty) was about 15 MPG.



Now with 7000 miles on the truck, I get about 17MPG empty.



My first tow was 9MPG, my last tow was 11. 11 MPG.



So my truck is improving, both towing and while running empty.



I have noticed that head winds plays a big part on fuel milage while towing.



Bob

 

[.44 mag]

Howdy Steve,

Should'a got the 4. 10's and bigger tires... ... ... ... ... .



Honestly, is that milage off the trip computer or an actual calculation? We went up to the Sierra Butes this weekend and got an actual 15+ mpg average. That was driving hard up hwy 80 then hwy 89 to about 6000 ft and back. We weren't towing, but I'm happy with that. We got about 3000 on the truck now too and it seems like the mileage is getting a bit better. The engine was right in it's power band at approx. 2000-2200 most of the trip.

I bet it still got you there better than that Durango you've been pulling that trailer with... ... ...



Hank