Tow Mileage Stinks. Suggetstions?

[JFortney]

I just did a 4000 mile road trip . I have a dually with 373 gears 4x4 and the auto. I have a slide in Lance slide in camper that weighs about 3400 dry and was pulling a jeep on a trailer I usually weigh in at 21500. I averaged about 10-11. 3 going west from Ohio through Indiana through nebraska ending in Colorado. Depending on what day or time there was a constant head wind which I could feel shakeing the truck. on the next day it was quiet and my milage went up to the 11. 3. and coming home from Colorado to Ohio I averaged about 11. 4-5 still getting a stiff wind out of the south most of the way. It really didnt quiet down until the last day coming home I got about 11. 5. This was done at the speeds of any where 67-70. It was actually better than the 5. 9 I had which only got me 9-10 and as low as 8 doing the same trip. So I am really pleased with how my truck preformed. Hopefully it will only get better. it has about 22000 miles on it now.

 

[AMink]

My trailer pulls better (less bounce) with the water tank full. It's an effect of tongue weight. The tank is forward of the axles. As noted, your truck should sit within a 1/2" at either end with your trailer at it's traveling weight. Take some time to level it out. Measure the front and rear bumpers, then adjust your hitch height and weight distribution to match that. Also, if you're running the ST 15" tires, 65mph is max. It sucks, but so do those tires. If you're planning on running at anything over 60, especially when it's hot, either get LT tires or don't go that fast. I (and many others) have had terrible luck with ST tires, no matter the brand. Heat, speed, and age seem to really kill them.

 

[icman95]

I'm going to whole heartedly agree with AMink about the ST tires. Just go back from a trip where 2 of them blew out on my RV. Check out my post here: https://www.turbodieselregister.com...214310-what-special-tools-do-you-carry-2.html



It's the last one on page 2 (post #30). It tells all about the crappy ST tires.

 

[EForbes]

Dont know about your state but most i have passed through, it 55mph max while towing, for safety mostly, but it will also save tons of fuel. You cant expect any kind of good mpg, racing down the highway at 70mph, pullin 6800lbs. its like having a parachute behind you.



For safety i would check the bearing rating and speed rating of trailer tires before going that fast.

 

[icman95]

Between CT and SD there is only one state that has a 55mph limit for trucks/trailers-Illinois. Ohio use to have the same thing, but changed it. I'm told that it was about a month ago for that change. SD speed limit is 75 for everybody and they all do at least that. The faster speeds do take a toll on the fuel mileage, but if you don't mind, then what the heck-go with the flow.

 

[LBARTLETT]

gsbrockman, you should have bought the old Airstream, looked really sweet behind your blue truck with that blue stripe!! really a sweet trailer for a 88'



great wheels on your truck too!

 

[gsbrockman]

gsbrockman, you should have bought the old Airstream, looked really sweet behind your blue truck with that blue stripe!! really a sweet trailer for a 88'



great wheels on your truck too!

Thanks for the compliments !



Greg

 

[CYauch]

My trailer pulls better (less bounce) with the water tank full. It's an effect of tongue weight. The tank is forward of the axles. As noted, your truck should sit within a 1/2" at either end with your trailer at it's traveling weight. Take some time to level it out. Measure the front and rear bumpers, then adjust your hitch height and weight distribution to match that. Also, if you're running the ST 15" tires, 65mph is max. It sucks, but so do those tires. If you're planning on running at anything over 60, especially when it's hot, either get LT tires or don't go that fast. I (and many others) have had terrible luck with ST tires, no matter the brand. Heat, speed, and age seem to really kill them.

Thanks. I just returned from a week long trip to Illinois, and haven't hand figured my overall mileage for the trip, but I didn't reset the overhead and it was showing 9. 6. Occasionally got over 65 mph to pass, but overall, was kept between 60 - 65. Mileage was better (obviously) the less hills I went thru. Someone mentioned to not drive 70 with a trailer, and well, i don't make it a habit. It was just for the brief trip when we bought it that weekend, and to see how this truck compared to the 01 with that much weight. I know mileage went up on my 01 the older it got, so i expect similar with this. For this longer trip, I didn't get to crazy with it.

Your tire story is a good one. Yes, i got bit on this trip. First, on the way back, we stopped at a rest area to eat on I-74 between Bloomington and Champaign, IL. While walking around, i noticed an orange sized blister in the sidewall of one trailer tires (TaskMaster). Changed out with spare, and moved on. No local dealer for the TT manufacturer, so decided to keep going. Made it southern IL and stopped for night. Got up next day, noticed spare looked low, so added air. I then noticed a thin blister start to form in the sidewall of the spare! Called warranty people (great people by the way). They asked how we did from the previous day (as we called to find the closest dealer to have tire replaced under warranty), then told me to go to the nearest wally world and have the two tires replaced asap. They would send us a check for the cost, and since we had two major tires issues, sent us 5 new tires, radials, mounted on new rims! Great people! Lesson learned. Will post pics of the old tires in a few as the camera is still in the trailer.

 

[JERRYDODGE]

I just got back from a 7500 mile trip to British Columbia. Tall mountains up there. ulling a 29' 8000lb Titanium. . Pointed nose. . Drove at 1750 rpm, 68 mph. some days got 11mpg (pencil), some days less. Wind big factor. Regeneration big factor. Pulling trailer 68, could go 190-200 miles between re-gen. (edge insight). no trailer, slow driving, site seeing, maybe 40-70 miles between re-gen. Also, before i started trip, went to check air on trailer tires. 2002 trailer. Maybe 8000 miles on tires. I noticed they were made the 42 week of 02. looked brand new... I didn't want to, but replaced them before we left. I keep them covered, but they are OLD and problamatic... Truck ran like a sewing machine...

Why do you 5th wheel guys pull your trailers 70-75mph? Because we can!!!

 

[BLarkman]

I went from 18-22 after about 15-20000 miles, It does get better, keeping under 65 or 1700 rpm also helps. It does take a while to break in.

bob

 

[Ken Keeler]

I have a 2007. 7 2500 mega Cab with 124,000. I'm using a smarty JR to manage EGR and DPF deletes with a aluminized 4" exhaust. Programming set to economy. Non towing mileage is 20-21, as soon as I put a v-nose 22' 7'x7' cargo trailer behind me and do the same speed I drop to 12. I talked to a tech instructor this week and he said he had the same problem with his 5. 9 and was told to reduce the down pipe back to 3" to increase back pressure to get the turbo to spool up faster. Has anyone heard this? Mine does seem to lug a little but if I get on the pedal it does go well. Any suggestions would be great.

 

[AHarris]

Last year I towed my 30' (8500#) camper and about 1500lbs of extra stuff from Louisiana to Wisconsin. During the first two tanks, I let the transmission decide by itself what gear it wanted to be in as I set the cruise at 67mph. Hand calculated, I averaged 10. 1mpg. For the rest of the trip, I limited the transmission to 5th gear. The engine sounded better and there was no more hunting every time I passed someone or came upon a hill. Hand calculated fuel mileage on the rest of the trip went up a little but to 10. 7,

My old 2007. 5 3500 with the G56 averaged 12. 3 hand calculated pulling the same trailer and didn't seem to work as hard doing it. For that and a couple other reasons, I really miss that truck.

 

[AH64ID]

I have a 2007. 7 2500 mega Cab with 124,000. I'm using a smarty JR to manage EGR and DPF deletes with a aluminized 4" exhaust. Programming set to economy. Non towing mileage is 20-21, as soon as I put a v-nose 22' 7'x7' cargo trailer behind me and do the same speed I drop to 12. I talked to a tech instructor this week and he said he had the same problem with his 5. 9 and was told to reduce the down pipe back to 3" to increase back pressure to get the turbo to spool up faster. Has anyone heard this? Mine does seem to lug a little but if I get on the pedal it does go well. Any suggestions would be great.

I would not go down to a 3" exhaust, all the back pressure you need comes from the turbo. If you add pressure to the exhaust post turbo you can cause flow issues. 4" is not too big for your truck, but 3" is too small. The turbo is variable and controlled by the ECM, a smaller exhaust would not have any measurable effect on boost and honestly the truck fuels harder with more boost so mileage may drop more.

What Smarty Jr settings are you using?

What speed?

Are you hand calculating or using the overhead for mileage?

 

[TJJEEPER]

2012 1 ton 4x4 with 3. 73 gears towing ~15,000 lb 5th wheel (37 1/2 feet long). When the truck was new I would get in the 8 MPG range. Now it has 4,000 miles mostly towing and it has gone up to 9. 5 MPG. This is on the same trip out to play in the desert every month with a few trips out to the coast. At first I wasn't happy but now I am. Specially pulling the hills @ 55 MPH without breaking a sweat. BTW I cruise at 58-60 mph. Speed limit in Cal is 55. Engine is 100% unmolested.

 

[icman95]

I'd be happy with 12. My 5. 9 gets 10-11 pulling my 5th wheel toyhauler depending upon exactly how I have it loaded and how I'm driving. On 2 different trips to the midwest where the speed limits are higher, I was in the 9-10 mpg range and in South Dakota where the limit is 75 and most people are doing a bit more than that I went down to 7. 75 on one tank. That was going a bit faster, though. 12 seems about right pulling your trailer to me.



Good luck.

 

[HBarlow]

TJJeeper and ICman95 are honestly reporting their fuel mileage which is similar to my experience and thousands of other owners.

There are no magic tricks available that will allow trucks towing large and heavy trailers with large frontal areas to overcome the laws of physics. Moving heavy masses against the strong resistance of air or even strong winds requires power and power consumes fuel. It's easy to spend thousands of dollars trying to compete with the fictional tales of great fuel mileage reported by some but you will never succeed. It's cheaper to do what they do - simply make up whatever story you want.

 

[AH64ID]

It's common knowledge that the 6. 7 uses more fuel than required to make it's power. While it is against federal emissions laws to adjust it the motor is capable of quite a bit more efficiency. It's nothing magic, just proper tuning. The last of the HPCR 5. 9's, which were more fuel efficient, used 400+ hp of fuel to make 325hp. A few tweaks to the tune and one could pick up 100 ft/lbs of torque in the mid range and NO additional fuel. That means for the same load you are using less fuel, and its NOT magic. The 6. 7 can be tuned for similar gains, possibly even greater.

So while the load on the motor will be the same, the motor could be made more efficient.

 

[AHarris]

TJJeeper and ICman95 are honestly reporting their fuel mileage which is similar to my experience and thousands of other owners.

There are no magic tricks available that will allow trucks towing large and heavy trailers with large frontal areas to overcome the laws of physics. Moving heavy masses against the strong resistance of air or even strong winds requires power and power consumes fuel. It's easy to spend thousands of dollars trying to compete with the fictional tales of great fuel mileage reported by some but you will never succeed. It's cheaper to do what they do - simply make up whatever story you want.

Thanks, Brilliant One for clearing that up for us. Now, everyone throw away your tuners and forget about improving your fuel mileage. The Great Oracle and Expert on Everything Barlow has spoken: there is NO WAY to make your 6. 7 more efficient or get better fuel mileage and anyone who claims otherwise is a liar and a communist. That is all.