Fuel Mileage When Towing a Load.

[jbrandonwagner]

I would like to hear what kind of fuel mileage you are getting when towing a load (and the size\weight of the load). I have a Early 2007 (LBZ) crew cab 3500 Dually with the 6 Allison 4wd 3.73 rear that is about 7000 miles old and I feel my fuel mileage is way too low. I am in the trailer business and I travel a lot pulling heavy goosenecks. On recent long highway trips, running empty at around 70-75 I would get about 13.5-14 MPG. When I hook up to a small trailer (18ft dual axle lowboy empty 2000lbs) It will drop to 11MPG. When I hook up to a larger trailer (25'-30' Dual tandem dovetail Gooseneck 5500lbs empty) It will drop down to 8-9MPG. If I put my tractor up on the trailer (Older International 656 about 6000lbs + 5500lbs of Trailer = 11500 Total) It can drop in the range of 7-8MPG. My alltime worst was yesterday, (44' gooseneck with a 40' gooseneck on top of that for around 15-18,000lbs total) will drop my mileage as low as 6.5MPG in some hills and 8MPG on smooth ground. All of these figures are for EMPTY trailer (except the tractor example). I expected better than this when I spent 45K on a truck. Is this normal???

[ob_1jr]

have you changed your fuel filter since you bought it? You may not like it, but try driving no faster than 60 or 65 and see if it helps your mileage. I get about 10-14 mpg towing a 24' enclosed snowmachine trailer (car hauler) with 4 mountain sleds in it. that is winter and mountain driving. In the summer, I get 17-19 empty driving about 70 mph (that is 2000 rpms for me). With all the new emissions stuff on the new trucks and ULSD, that could be causing it your low mileage. I have a first generation engine, so I have a totally different animal than you. Very few people see the 20 mpg mark that I have often heard. The best I ever got with mine was almost 21 with stock tires on. Right now with the winter driving and super cold temps(-20 to -30F) up here, I saw 12 mpg unloaded going to fairbanks and back to eielson (about 25 miles one way). I did idle the truck for probably a total of 45 mins on this tank. I have heard that people are unhappy with the mileage they are getting on the new trucks. You might want to go to the dealer and see if there are any software updates for your truck. Other than that, I don't know what to tell you.

[duramaxdavid]

That sounds about right from what ive heard. Ive got a friend with an 06 dually and his average is 7 or 8 mpg. 90% of the time hes got a gooseneck full of cattle behind him.

BTW, welcome to the site.

[05_LLY]

Biggest load i everhauled was a 73 chevy with a 6" lift and 40's on it @ 6000lbs, on top of a 22'over the axle adjustable beavertail Cornpro trailer @4700lbs so a big high (lots of wind resistance) Load weighing 13k on a 350 mile trip i avg.13mpg with a 90 hp efi tune loaded!!!

[mikerinaz]

I pull a 28' toy hauler, loaded up with gear and bikes it is about 12,000lbs. I'm pulling it with a stock '06 2500HD w/ LLY, mostly mountians and 65+mph, I'm getting 8-9MPG (I can still pass anyother truck pulling a load uphill) Not bad all things considered, I'm hoping to see some increase after some mods.

[cumminskiller]

I haven't pulled any loads yet (plan on pulling the wife's SUV through the mountains when I move to Washington next month @ 5000 ibs.), the truck has only 650 miles on it. On the first two tanks I was averaging a hair under 16 mpg, and most of its city driving. Just food for thought...my dad who is a retired truck driver said that if the Duramax is tuned slightly wrong it can cause bad gas mileage. I thought he was smokin crack, but maybe there is something to it, never know.

[Kawtipping]

Originally Posted by ob_1jr

With all the new emissions stuff on the new trucks and ULSD, that could be causing it your low mileage. I have a first generation engine, so I have a totally different animal than you. I have heard that people are unhappy with the mileage they are getting on the new trucks. You might want to go to the dealer and see if there are any software updates for your truck. Other than that, I don't know what to tell you.

The trucks built before January 1st will not have the new emissions or ULSD on them. My dad went looking to buy a new one, and was told by the dealer that if he wanted a new truck, he better get one quick before they put all the new emissions equipment on. He ended up ordering one out about 3 weeks ago...on the condition that it must be one built before January. I was surprised to hear that his new truck will be in by the first week of December! And I always thought it took longer to have a truck built to order!

As for low fuel mileage, remember your engine is not even fully broken in at your current mileage. Look for your numbers to increase as all the parts "get to know" each other!

[JMD]

Originally Posted by jbrandonwagner

I would like to hear what kind of fuel mileage you are getting when towing a load (and the size\weight of the load).

Recently I have bought 2 new identical trailers, 28' high profile van trailers. I picked up each of them about 10 days apart. Each one was towed from Springdale Arkansas to Las Cruces New Mexico. The first trip I drove a Ford F-350 V10 at about a 70 MPH average speed and I got about 6.5 MPG (computed). On the second trip I took a 2005 Chevrolet C-3500 Duramax, I got about 8 MPG (computed) at about the same speed (maybe a little faster )

The Chevy had a performance advantage, but all in all both trucks performed well. Considering the 50 cent a gallon difference, the cost of operation was very close, possibly advantage gasoline, (I dont like it, but this seems to be reality).

I am involved in a family bussiness that has been utilizing 1 ton truck and trailer combinations since 1974, and all in all the numbers that you have posted seem reasonable to me, albeit I would expect to see your mileage increase slightly as the truck begins to break in.

There are a lot of claims made about mileage that I find difficult to believe because there is really no magic bullet, when towing trailers, it takes a certain amount of energy to do certain amount of work, with usually only small diferences due to certain efficiency issues and the related issue of emissions. It is my opinion that the main issue when it comes to fuel efficiency, is the driver and his or her driving habits.

You will hear alot about the weight that a truck pulls when trailering, but it is my opinion (and experience) that the primary concern is wind resistance. (ie: energy lost pulling a heavy load up a hill can be partially recovered going down the other side of the hill, energy lost to wind resistance is never recovered, (unless you always drive downwind )

If you want to drive 75 when trailering, (I do), you need to be willing to pay the price at the pump. For bragging rights I could have coaxed more mileage out of both of these trucks by moderationg my driving habits, but whats the fun in that?

[ob_1jr]

Originally Posted by Kawtipping

The trucks built before January 1st will not have the new emissions or ULSD on them. My dad went looking to buy a new one, and was told by the dealer that if he wanted a new truck, he better get one quick before they put all the new emissions equipment on. He ended up ordering one out about 3 weeks ago...on the condition that it must be one built before January. I was surprised to hear that his new truck will be in by the first week of December! And I always thought it took longer to have a truck built to order!

As for low fuel mileage, remember your engine is not even fully broken in at your current mileage. Look for your numbers to increase as all the parts "get to know" each other!

Actually the ULSD fuel is out and being used in some stations depending on where you live. Just having the cat and egr on the trucks decrease the MPG. My truck doesn't have any of the emissions stuff on it...never came with it...it's a LB7. I do agree with the mileage not going up at low miles. My truck is just getting broken in at 42000 miles.

[Kawtipping]

Originally Posted by ob_1jr

Actually the ULSD fuel is out and being used in some stations depending on where you live. Just having the cat and egr on the trucks decrease the MPG. My truck doesn't have any of the emissions stuff on it...never came with it...it's a LB7. I do agree with the mileage not going up at low miles. My truck is just getting broken in at 42000 miles.

ULSD...got my acronyms confused. To many 3 and 4 letter terms out there now! Anyways, I do not believe we have seen the ULSD fuel here in Wisconsin yet.