Hi, I'm new - here and w/ a diesel truck - I have a '05 f250 crew cab, short bed, 6.0, 4x4 w/ just under 20k miles.

I'd heard great things about towing w/ diesel so I went and bought one - but as I've seen I have a to learn about these trucks. and so far I haven't had any decent advice - because as I've seen everything I've heard has been .... mixed?!!<O</O

So to everyone out there that are veteran diesel owners, please help me out!!!<O</O

<O</O
First, diesel - is it still ok for me to just fill up w/ the regular diesel available? I don't need an additive in my truck when I fill up? An old mechanic friend of mine told me I did, then someone else told me I didn't. so far I haven't.<O</O

I put on an Airaid air filter, leveled it w/ a two in. front spacer and added 20" wheels w/ 35" tires. <O</O

I bought the truck to tow a 5k lb travel trailer 24ft. long. This weekend was the first time I was towed it. We towed it about 200 mi. each way. Compared to my gas SUV, this one felt great towing. But it wasn't quite what I was told it would be like. Would my wheels and tires make that much of a difference??<O</O

 

(CONT'D)

I've been told by a lot of f250 owners that when you tow there's not a lot of difference in miles per gallon - w/ mine there was, my truck was doing under 8 mpg, normally it does double that.<O

I had also been told that they could "fly" while towing a trailer - I really didn't expect that, but I did expect to be able to tow at the speed limit - usually 75mph - I couldn't, I had to stay at 65mph - as I could feel the truck straining above that.<O

What about the turbo gauge - what's normal, what's not? Where do I want it to be at, when towing or not?<O</O

Would it be better if I add it a chip and gauges?<O</O

Also, I didn’t use the tow/haul button because I didn’t like the feel of it. I used it for the first part of the trip and the gas mileage was just as bad. The transmission was taking a long time to shift – my gas truck(an ’03 Denali) used to do the same thing when I used the button. Is it supposed to be that way? If so, why do they do that?<O</O

Anything I've missed that I should take into consideration w/ diesel? As I've always been a gas owner.<O</O

I think people just raised my expectations of diesel more than I expected - but I really expected the MPG to be better. Thank you for your time and maybe this will turn into a good discussion.<O</O

 

Well, lets start by saying welcome to the site. You'll find it informative and a great way to get answers too.

Let me tell you that I'm new to diesels too. All of my other trucks (F150s and Rangers) have been gassers. Right now I have the luxury of having my old 150 and this new (to me) 250 diesel. My 150 had a button to turn off OD when towing or hauling big loads.

I've found that the tow/haul mode works pretty much the same way. If I'm lightly loaded or on pretty flat ground I don't use tow/haul mode. I just came back from NH and towing a trailer full of household goods, mine was pulling at 75-80 and had power to pass at will. My mpg dropped from 14.9 to 14.6 while I was towing so needless to say I was pretty impressed.

That being said, every truck is different. I bought mine in mid Feb...it had 34K on it then and I now have 42K on it....so I'm driving the heck out of mine and loving every minute of it.

Trying to compare towing with my gasser (a 351) and the diesel is day and night. With the gasser I felt I had to always anticipate a move that required more power in order to let the power build up to what I needed. In the diesel....I just stepped on it and the truck started moving right out. I always felt I was pushing the gasser when I towed big loads....not so in the diesel. It's almost like the diesel is laughing at me and saying 'is that all you've got to throw at me?'

As for additives....I use Power Service Diesel Kleen at each fillup. Remember when fuel went from leaded to unleaded? Think of us going from low sulpher diesel to the new ultra low sulpher diesel the same way. The additive is helpful for motors built before they had ULSD. I personally think that I've seen a slight mpg increase using the additive. I would not hesitiate to recommend it to any of my friends running diesels.

Good luck pal!

 

I use an addative but it has never made any improvement in milage or performance I could tell...more of a piece of mind against bad fuel...based on your milage I'd have to say that maybe your size tires are affecting your trailer towing milage...mines all stock and I avg. mid 15's around town...I tow a 7500 lbs. TT and run at 68 mph with tow haul ON...last trip was just under 3K miles I averaged 12.11mpg...in 7500 miles of towing my worst was 10.65 mpg going over several passes in one tank...best was 21.65mpg (towing on flat ground).

 

First off.... Welcome to the diesel community.

Second lets get to your questions. What was your original tire size that was on the truck when new? This will be on the door tag. Probably 16 or 17". By going to the 20" tires and 35's you are adding a lot more torque to the drive train to get moving or keep moving VS the standard tire. Thus it will use a lot more fuel as you add weight than would be normally used.
Diesel fuels... These engines was designed to run on low sulfur so there won't be much difference because they knew the ULSD was coming. But if you try a fuel conditioner and it seems to run better. I would continue using it. Won't hurt.
If you had an older diesel then I would say use a conditioner all the time.

Also check with your service department on using the air filter you put on. The warranty states that it could void warranty. I would ask to be sure.

On our 04 we get 16-20 MPG solo and 12-14 towing trailer.

 

I'd go back to the stock airfilter it flows more than enough air for the engine, also you run the risk of dusting your turbo with an aftermarket airfilter, also could viod your warranty.

 

Thank you all for the welcoming. After all the research I've made, I'm taking in my truck to the dealer on Monday - the bad MPG is a sign to have it checked. Thank you all for your responses and time!

 

When you get a chance, be sure to check out our 6.0 Tech Folder. Lots to read there. Here's the link:

https://www.ford-trucks.com/forums/3...ch-folder.html

 

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Be sure to reinstall your stock intake the dealer could deny warranty do to the intake if they are as strict as mine is.

 

You have to recalculate your mileage considering the 35" tires, yes you changed the gear ratio and shift points. The rim size is mute in the equation, switching from 17 to 20" rims will give you more stability because of less side wall flex in the tire, over all diameter is what your looking at.

 

Also, after reading most posts through out the site, seems like not very many people are fond of the aftermarket intakes. So basically, just get rid of mine? Can anyone tell me why they're so bad? I had one in my f150 and it increased my MPG. THX!

 

The problem with aftermarket air filters on the 6.0PSD (potential warranty issues excluded) is that for an aftermarket air filter to flow more air the hole sizes have to be larger, the larger hole sizes also allow more dirt into the engine. More dirt passed by the air filter is hard on the engine and turbo.

The Donaldson Powercore that came on your 6.0 flows for air than the 6.0 can use until you get to extreme power levels (this takes more than a tuner, it takes injector and fuel system changes also). So by changing to an aftermarket air filter on your stock 6.0PSD you will see no performance gains, but you will have decrease filtration. So put your stock systme back on.

Since you pull with your truck, you need to add some gauges (EGT & Trans temp).

As Maxium4x4 said, changing your tire diameter can have a large effect on performance. By increasing the tire diameter you have effectively installed taller gears in your diff. This translates into lost performance as the PCM, TCM etc monitor what they think is correct input from speed sensor and adjust accordingly. When you go to larger tires you need to have your PCM recalibrated to account for the larger tires and if the tire size increase was much over stock size, you will have to re-gear to get your performance back. Since you have a 4x4 you must re-gear both axles.

You should see an increase in MPG as you get more miles on the truck, breakin does not fully occur on these until 25-35K. Also go by a CAT scale and weigh your truck and trailer fully loaded, you may be suprised how much everything weighs.
When i tow i get 8-12MPG (depending on load & terrain), empty in town 14-15MPG and empty highway 16-19MPG. Fuel mileage varies do to many factors.

Hope this helps

 

Most do not filter as well as the stock system. As a result the dirty air enters the turbo which is spinning at an incredible rate. When the dirt comes into contact with the turbo it causes damage to the blades which in time will cause the turbo to not produce as much boost and you loose power. The Ford filter also will not pass water, which can also cause turbo damage. Many after market air filters use an oil soaked air filter for filtration, the oil can damage many things going thru the intake system. If any one of these things or many others I have not thought of happen to your engine and you take it to the dealer for repair they can deny the repair due to the after market air filter. The stock Ford air filter works very well and flows as much air as the engine needs and your warranty stays intact.

 

1Rosario! Welcome to this site, I am new to the site, but have had several diesels. I think everyone gave you some good , sound advice. Folks are pretty friendly and share on this site!! Cool! I was wondering where you live if you are expecting to tow at 75 mph? Not in California I hope. Officer Friendly of the CHP out here in the desert, dearly loves to catch trucks towing fast. So wherever you live, tow safe, get there, have fun, and get home safe!! Good luck! GOD BLESS OUR TROOPS!!! DALEDIESEL