I have a 2005 Chevy 3500 Dually 4x4 Crew Cab. I tow a 38' Fifth Wheel that weighs around 15000 pounds.

When towing, I get 12.5 mpg at 55; 10 mpg at 65; and 8.5 mpg at 70. I just met a man towing the same weight with a Ford F350 Dually. He gets 12.5 at all of those speeds.

Is there any way to improve the fuel economy of this truck?

If this is in the wrong place, please feel free to let me know or move it.

Thanks
Pastor J

I am using a Kennedy EFI Live tune, and it is definitely helping. I have had my best ever empty mileage with it. My towing mileage is up also, but with all the variables it's harder to pinpoint the exact improvement. I would guess about 10-20% increase towing.:)

He may be towing the same weight, but is it the same profile? Every Ford, Dodge or Chevy owner I have talked to get's about the same mileage you get at the speeds you listed. I tow a 37' 5er and get numbers similar to yours. Other than adjusting the tune or drafting another large profile vehicle, there isn't much else that can be done.

Thank you for the responses. I was just surprised by the difference

When towing, I get 12.5 mpg at 55; 10 mpg at 65; and 8.5 mpg at 70. I just met a man towing the same weight with a Ford F350 Dually. He gets 12.5 at all of those speeds.

I think a lot of guys talk about fuel mileage like they do measurements. He also has a full 6 inches!

I have had a Ford 7.3 and anything over 68 MPH the fuel mileage suffered severly

I also have an 05 3500. I put a cold air intake and 4 inch exhaust on it. Pulling a 39' 5er weighing 14 to 15k (depending on what toy I have with me) standing 12'6" tall. If the wind isn't blowing hard :lol: I get about the same #'s at the speeds you mentioned. No matter what kind of truck owner I have talked too with similar size trailers they get about the same.

Jim

I have a 2005 Chevy 3500 Dually 4x4 Crew Cab. I tow a 38' Fifth Wheel that weighs around 15000 pounds.

When towing, I get 12.5 mpg at 55; 10 mpg at 65; and 8.5 mpg at 70. I just met a man towing the same weight with a Ford F350 Dually. He gets 12.5 at all of those speeds.

Is there any way to improve the fuel economy of this truck?

If this is in the wrong place, please feel free to let me know or move it.

Thanks
Pastor J

With all due respect to your friend.... he can't possibly get the same (12.5 mpg) at those varying speeds. Physics is the same for everyone.

DEWFPO

Couldn't agree more. I think it is like the fish story mentioned above. I know a guy that claims 14 mpg pulling 14k with a 04 2500 an I just say rightttttttt!!!!!!

get a wing

With all due respect to your friend.... he can't possibly get the same (12.5 mpg) at those varying speeds. Physics is the same for everyone.

DEWFPO

Yup! :exactly:

get a wing

:offtopic:

:offtopic:

Not necessarily off topic. He asks if there is way to increase fuel economy. The sites that sell the big wings for pickups that pull fifth wheels say that one can get 3-4 miles per gallon increase.

Does anyone use the wing? Can you verify that it is a way to increase fuel economy?

From what i've been reading on the subject, about the only ones who are
so sure that they increese your mileage is the one's selling them. Most of the
people see no real increse. I thought about it, but don't believe I can save enough to make it worth while. Just my .02

I tow 13,000 lb fifth-wheel with a 2004 dually. Same general MPG as yours.

So I guess the wing is the same as the bed cover or driving with the tailgate down??

I know when I bought my bed cover, I had it paid for with the fuel saved by the time I got home!!!

Yeah right!!

Good thing for me, I bought it to keep my stuff dry, not save fuel!!

Ken

I think a lot of guys talk about fuel mileage like they do measurements. He also has a full 6 inches!


:eek: I just got that...I feel so inadequate.


Anyways, once you have the "Drive below mach-1" thing down, and it sounds as though you do, the next thing is do whatever it takes to keep your truck in overdrive longer. Next to driving slower, keeping RPMs lower via gear selection is the best way to improve economy. So if your vehicle has a tow tune on it even though your are making more power, you are able to stay in overdrive more often without the tranny shifting down into 4th. Next, Insure proper tire pressure. I gained .4 mpg by adding 8 pounds of air (60 psi to 68 psi) to my wife's 2500 Sub on a trip to TX. Lastly, taller narrower tires can help, i.e. on a dually, a set of 235/85/16's may help slightly, but not enough to cover the cost of 6 new tires if the ones you have now are in good shape. HTH.
JP

I have a wind deflector. It did add about 1/2 a mile per gallon. To me, not worth the aggravation. I was hoping for 1-2 mpg increase. 10 mpg would have been nice, but I think the only way I will get there, is to slow down to about 60mph.

Anyways, once you have the "Drive below mach-1" thing down, and it sounds as though you do, the next thing is do whatever it takes to keep your truck in overdrive longer. Next to driving slower, keeping RPMs lower via gear selection is the best way to improve economy. So if your vehicle has a tow tune on it even though your are making more power, you are able to stay in overdrive more often without the tranny shifting down into 4th. Next, Insure proper tire pressure. I gained .4 mpg by adding 8 pounds of air (60 psi to 68 psi) to my wife's 2500 Sub on a trip to TX. Lastly, taller narrower tires can help, i.e. on a dually, a set of 235/85/16's may help slightly, but not enough to cover the cost of 6 new tires if the ones you have now are in good shape. HTH.
JP

I keep pressures up in the tires both on the truck and on the trailer. Your comment about overdrive makes sense. I found that when I am towing in the "tow/haul" mode, the trans stays in a lower gear longer, even if its not needed. I found that if I switch out of "tow/haul", I can get it to upshift sooner, especially on level ground when not struggling. I don't know yet if that helps the mileage, but it seems to me that running around in 3d gear when you could be in 5th would save fuel. Am I wrong?

... but it seems to me that running around in 3d gear when you could be in 5th would save fuel. Am I wrong?
No, you're not. Sometimes I switch out of tow/haul just to get the trans to upshift, then I go back to tow/haul, this keeps the trans temps in line. I was mostly referring to adding a tuner so that there will be more HP available while in OD and because it has more HP it can pull the hills, or against the wind much longer before shifting out of OD. Since I added my Banks tuner the trans rarely shifts out of OD. Now, my 5ver is only about 9500lbs, but driving to WV there are some purty long hills and she stays in 5th most of the time. And, as I type this I am at Loyola University in Nawleans and drove down from IN. I was running solo between 73 - 80 mph and I finally broke the 20 mpg mark at 20.2 miles per gallon. Not bad for a 7300lb brick w/ 4wheel drive. :ro)
JP

I was running solo between 73 - 80 mph and I finally broke the 20 mpg mark at 20.2 miles per gallon. Not bad for a 7300lb brick w/ 4wheel drive.
JP

Not bad at all.

I have a wind deflector. It did add about 1/2 a mile per gallon. To me, not worth the aggravation. I was hoping for 1-2 mpg increase. 10 mpg would have been nice, but I think the only way I will get there, is to slow down to about 60mph.

The way I look at it is try pulling the same weight with a gas and see what you get. I think you'll be happy with what you are getting with the diesel. My 1st camper weighed about 4k and I pulled it with a Z71 and was lucky to see 10mpg with it.

What aftermarket parts will help with this?? The way I look at it is these trucks have enough power so I don't think more of that is needed except like mentioned, it will help to stay in a higher gear. Could mpg gains be expected from larger exhaust, blocking the EGR, etc???

With the cost of fuel these days, you could buy a lot of add on toys and a few MPG would pay for them for you!!

Ken

What aftermarket parts will help with this?? The way I look at it is these trucks have enough power so I don't think more of that is needed except like mentioned, it will help to stay in a higher gear. Could mpg gains be expected from larger exhaust, blocking the EGR, etc???

With the cost of fuel these days, you could buy a lot of add on toys and a few MPG would pay for them for you!!

Ken

I put a cold air intake and a 4" exhaust on and saw maybe 1 or 2 mpg empty. When I dropped th14k onto her I did'nt really see any difference. Maybe 1/2 mpg. I'm leaving Sat. on a 350 mile trip. (The furthest I have pulled since I put it on.) I'll let you know more when I get back as I plan to monitor it at different speeds as close as possible.

Jim

What aftermarket parts will help with this?? The way I look at it is these trucks have enough power so I don't think more of that is needed except like mentioned, it will help to stay in a higher gear....
Ken

Well, tuners do more than just add power. The exta power comes from optimizing vehicle perameters to insure peak operating performance. The larger exhaust helps in reducing EGTs (exhaust gas temp) which is unspent fuel in the exhaust heating up. The trick is instead of wasting that unburnt fuel, use it to make the extra power, then you have more oomph with better fuel mileage. As far as an aftermarket intake goes, you will probably not need anything more than the stock airbox with an AC Delco paper filter. I've tried a couple other drop-in filters and experienced no difference in seat of the pants performance, or in observed fuel mileage increases. I really can't speak to the EGR block-off thing or what you can expect if you do it.

If you bought your dually truck mostly to tow your RV like I did, then I would suggest a good set of guages (boost & EGT), a 4" exhaust, and a mild tuner. This will make for a very good tow vehicle with a long service life. IMHO
JP

20k lbs total running down freeway at a constant 70-75 mph with wing I get 10mpg.Without it I get 8 to 8.5mpg.Plus no bugs on my trailer.I KNOW the wing works because I have one and have towed with and without it on the same stretch of highway on several occasions to test it.NUFF said.

Used a wing for 400,000 miles. No Gain. No wing on new truck. Your choice.

Oh !! It did keep bugs off the trailer!!! :lol:

I have an 06 Chevy Crew Cab Dually with the LBZ Duramax. The first 3 or 4 tanks I checked I got 10.2 towing a 36 ft. fifth wheel and some of the towing was in the hills of Tenn. and I was getting 16.1 solo. The last 3 or 4 tanks I checked was 8.5 towing and 13.2 solo, and I just filled up and 11.1 solo which most of it was town driving. The truck has 3000 miles on it. It seems like the older it gets the worst the fuel milage is. We are getting ready to take a 6000 mile trip to the West Coast and am wondering what i,ll get going thru some of the mountains.

I have a 28foot weekend warrior and I get 10-12 at 70-75mph

Here is what I got on my trip. Pulling about 21,500 at 70 to 75 in a hilly area (Central to western NC) I was getting right at 9.1. Running same weight same & area at 60 to 65 ran right at 9.9.

Just got back from a trip from San Dog to San Anotnio and back and I was about 65-70 mph at 10 MPG on a stock engine pulling my rig. Had some wind resistance but alot of hills in Tx and of course the mtn near Cali. I will chg the exhaust not more for mpg but for the lower egts. Regards...

Just got back from a trip from San Dog to San Anotnio and back and I was about 65-70 mph at 10 MPG on a stock engine pulling my rig. Had some wind resistance but alot of hills in Tx and of course the mtn near Cali. I will chg the exhaust not more for mpg but for the lower egts. Regards...

What kind of GCVW are we looking at? The guy that was with me on this last trip was grossing about 16k and was running in the 12.7 to 13 MPG range running right with me.
I also just put on the 4" down pipe / CAT Delete pipe to match the rest of my exhaust to lower EGT's. Longevity of the engine is what really counts. Will see at the end of the month when I do my next trip if it does anything for MPG.

What kind of GCVW are we looking at? The guy that was with me on this last trip was grossing about 16k and was running in the 12.7 to 13 MPG range running right with me.
I also just put on the 4" down pipe / CAT Delete pipe to match the rest of my exhaust to lower EGT's. Longevity of the engine is what really counts. Will see at the end of the month when I do my next trip if it does anything for MPG.

I don't gross out that much but the trailer isn't the lightest either. I'm looking hard at the down pipe and your exhaust but I am really concerned with having droning in the cab. So leaning towards Corsa, Borla or TTS. I definitely need longevity on military retirement pay ;)

I don't gross out that much but the trailer isn't the lightest either. I'm looking hard at the down pipe and your exhaust but I am really concerned with having droning in the cab. So leaning towards Corsa, Borla or TTS. I definitely need longevity on military retirement pay ;)

I know what you mean. I'm not retired yet but working towards it. Not to get :offtopic: I will tell you that the noise level in my cab with the 4" system didn't really go up that much. Still can talk back and forth with the radio on and not have to raise your voice.

Remember that the aerodynamic drag goes up with the square of the velocity--drag at 70 mph is almost twice that at 50 mph. (50 x 50 = 2500, 70 x 70 = 4900)

Remember that the aerodynamic drag goes up with the square of the velocity--drag at 70 mph is almost twice that at 50 mph. (50 x 50 = 2500, 70 x 70 = 4900)

Wont disagree at all as I live in an area where the wind will kick up and when it does I have seen as little as 8 MPG at 55 just fighting a head wind.

ford sucks

and the owners know that they cant say that the motors are good cuz its ford, so they all make up bs that they get like 20 mpg while towing their 15,000lbs 5th wheel

HAHAHA

me = :pimp:

my dmax= :bling:

Alright Guys I bought my truck two weeks ago and installed the Bully pup and at best I have gotten 18 mpg. I have 3000 miles on her. I have had her on the highway for 80 percent of the tanks. I was really expecting somewhere between 21 to 23 by reading some posts in here. Please Help. I don't get on her alot but I don't baby her either. I am running straight diesel no additive.

Alright Guys I bought my truck two weeks ago and installed the Bully pup and at best I have gotten 18 mpg. I have 3000 miles on her. I have had her on the highway for 80 percent of the tanks. I was really expecting somewhere between 21 to 23 by reading some posts in here. Please Help. I don't get on her alot but I don't baby her either. I am running straight diesel no additive.

I can't speak for the LBZ but when I first got my LLY it didn't do as good as I thought at 1st. I was seeing 14 to 15 mpg. I broke it in as close to the owners manual says to and I have came up to around 19 to 20 and an occasional 21. I tow most of the time so I don't get to check it much with nothing behind it. Break in is very important and it needs to be loaded as discribed or you wont get proper ring seal. This to can effect fuel milage and performance.