I agree with you, I had a cover on my last truck (F150) and id didn't help at all, i though the was a coincedence or something, I lost 1 1/2 miles per gallon after the installation of the cover.
TZ

 

you are right it did, keep in mind this is my first truck and I am new to this. well this the story when I left San Diego going to yuma I got 7 MPG pulling a 15k fifth wheel now coming back I got 5 MPG the wierd thing is the noise the Turbo makes sometimes when on a steep hill and it is already at 35 to 40 psi then it makes this very loud winning noise and i do not not why? is my turbo gone bad? is there something wrong with the truck? I have no idea why the MPG is really low I thing I shoold have the truck checked out.
Now when I bought my trailer 3 weeks ago I used my friends truck 2007 F250 6.0 4x4 3.73 LWB and I got 9.5 MPG pulling my fifth with it and his truck was loud but certainly not stressed like mine on this first trip. I am very disapointed and hopefully something is wrong with my truck that can be fixed I will refuse to drive it let me tell you on certain steep grade my speed got down to 40 MPH and I could not not understand why the engine RPM refused to go up to 5k or 6k rpm like it would in a gas engine.
let me tell you I spend 62k OTD for this truck and on my first trip I feel ike I got robed especially when you see chevys or dodges passing you by.
send me feed back let me what you guy think.........

 

Did you have the PCM recall done yet? That seemed to significantly increase my mpg issue. I went from 8 mpg in the city to 10.3 on the highway towing a 7500 lb travel from sea level to 5000 foot elevation.

I also noticed the peculiar noise the engine was making on the grades. The tow system does a nice job of keeping the tranny from switching gears until your rpms are over 3000 which saves your brakes on the downhill. However, I'm still not sure what that noise was but I know exactly what you are talking about. It almost sounded like water pressure release from one of the radiators making nearly a whistling noise. Maybe some of the experts here can diagnose it.

 

I own a 2001 Ford Excursion with the 7.3 diesel. I honestly average anywhere from 18 to 24 miles per gallon with a mix of highway and local driving. While towing I have had as good as 15 and as low as 9 miles per gallon. I tow different cars on a 2,500 pound equipment trailer. I know there may be some people that say there is no way I achieve this but it is true and I have no reason to lie about it. I do notice that whenever my miles per gallon begin to drop I change the air filter and this definitely does make a difference. I also do have the fuel filter changed every fifteen thousand miles and notice the miles per gallon get better at this point as well. I do not have any aftermarket equipment on my truck and do not intend on getting any. I am happy with the Excursion the way it is. My truck has the 3.73 gears in the rear and it has four wheel drive. I will add that I do believe that driving style has a lot to do with gas mileage as well. I personally realise that I am in a truck when I drive and I do not try to leave from a dead stop as quickly as the cars around me take off. While towing I stay in the right lane and do the posted speed limit and sometimes a little less depending on how the weight distribution on the trailer feels to me. I read in one of these posts someone whom said he was doing 82 mph while towing and would like to go quicker to pass people. I am not knocking him but I personally would never go that fast towing anything. I simply do not see that as being safe at all. I will also add that I live on Long Island in New York which is where all of my daily driving takes place so there are not a lot of steep grades here. While towing cars I actually go upstate and into surrounding states often (New Jersey, Vermont, Mass., Rhode Island, etc.). A lot of these places do obviously have mountain ranges and steep grades.
That being said; I have decided to buy a brand new truck. I was thinking of the F-450 but after seeing the gas mileage numbers and the fact that you can get it only with 4.30 or 4.88 gears I believe I will more than likely lean towards an F-350 with the 3.73 gears. With what I tow I suppose the F-450 would be overkill anyway. I will post what my miles per gallon on the new truck is once I purchase it but due to my driving style I suppose I will get better gas mileage than a lot of other people with the same truck.
Good luck to all with their trucks!

 

drisschoufa, I think that the noise you are hearing is the cooling fan. On my AZ trip, when pulling a steep grade, I noticed a sound that was similar to an over reving engine, but looking at the tach told me other wise. I think that since the engine was putting out so much heat pulling the grade, the fans kept spooling at hi to cool the engine down. Mine only did it for a minute or so. I haven't actaully popped the hood to see if it has electric fans, so this is only SPECULATION on my part.

Also too, when you used your friend's truck, did you pull that same grade coming out of Imperial County with a fully loaded trailer, or did you just drive around San Diego?

(Tip, dump your FRESH water tanks before climbing that grade, and use the dump station at the rest stop just west of El Centro, you'll have to wait in line, but you'll knock off over 1,000 lbs of weight in the trailer.)

 

i really hope you're seriously not trying to push it to 5k or 6k rpms.... cause that just might be your problem...

 

unless these new trucks are designed to do that... but i seriously doubt it

 

Mattebury, is it normal that your speed goes down to 40MPH on certain spots and is it normal the MPG that i am getting and I did damp all the fluids at Hidden Shores resort before leaving the funny thing is I find out that I had a full tank of fresh water when I got to the resort which I do not need there but the MPG was 7MPG going there and coming back with an empty trailer I got only 5MPG I am disapointed and honestly Mattbury I do not care so much about the financial part of it but the fact that I can not even go south as san felipe which 140 miles south of the border without an extra tank which means extra weight at 5MPG you figure 300 miles return to the border Calexico you need 60 gallons of fuel that is not right on todays tecknology you know I should of kept my gas motorhome and at least I could buy gas for it anywhere instead of this truck which limits us now of where we go.
It seems to me that you either get MPG or MPH and here I am not getting neither if my speed can not be over 40mph in certain spots climbing hills that is a problem and you add the MPH consumption then I am really not happy. we were getting 4 to mpg on our 34 feet ford motorhome gas pulling a trailer 5.5k pound just toys in it jetskis and quads and driving it everywhere including to Cabos San Lucas twice and now look we are getting worse and yes better performance but not worth the limitation and the fact that we can not buy fuel anywhere like before.
the bottom line I really think I scroud up buying this truck.
I am not loyal to any brand but this is not good I bought this truck because it looks good but aparently that is not very important when it does not perform as well and limits where you can go with it. this truck will be sold if it is going to be this way.
to all of you here do not buy this truck if you lifestyle is like mine Ford and the EPA can not and should not dictates where we can go in our life and by the way if you buy any new truck you will only be able to use the new 15 PPM diesel so what do we have to do now go and buy our trucks in some other country.

 

Get used to this crap, gas and Diesel prices have no where to go but up.

 

I have no problem maintaining speed at 60 MPH on cruise control, or climbing that grade out of Imperial County into San Diego (in fact, I pass a lot of toy haulers that blew by me on the flat doing 80). But, I am running 4.10 gears and only a 10,000 lb trailer, while you have 3.73's and 15,000 lbs (I'd look at Ford's towing guide, but I think that you have exceeded the recommended trailer weight for a 3.73). For me, with only 3,000 miles on the motor, to get mid 9's towing on a 1,100 mile trip to the Grand Canyon, I'm happy. It should gain a mile or two as the motor breaks in. I hear from a lot of guys on this forum that it takes around 25,000 miles to see what your "true" MPG is going to be.

This is my first diesel, so I'm learning too.

 

drisschoufa, nope, not overloaded at 15,000 lbs on a fiver. According to Ford, it's 15,700, so you are close.

 

Whoops, 15,200 lbs on a 4x4.

I was surprised to see that the 4.10 rear end has the same towing capacity.

 

I get 16 mpg every tank with my 2006 6.0 and it only has 17k on it, it's not even broke in yet.

 

I have a customer with a '05 Dodge 3500 4X4 with the Cummins and 3.73s. He has an Edge programmer and gets 24 mpg commuting to work and said he once got 30 mpg when pulling his car trailer from Salt Lake City to Reno. He says the secret is to keep the rev's below 2000 rpm. He also said the engine didn't come alive until 15k miles. My former boss just got a Duramax last winter and says he's getting 18 mpg to start. Reading this post depresses me as I was thinking of buying a diesel to pull my camper with.

 

The dodge gets better MPG cause its a 6 cyl, but still I was hopeing that the new 6.4 would get better but then its still less than 4 months since people started posting there mpg and who knows what will turn up.