Poll: Average speed you tow at?

[FreshAir]

I tow at 65 unless doorgunner is behind me on the radio asking me to slow down .

[Action]

It's 15mph in AZ.
>>>>>>>>>>>>>>Action

[Minnie's Mate]

In December I traded trucks and purchased a 2008 F-250 with the new power stroke diesel. The mileage with and without the Airstream in tow is considerably less than that of the '05. Unfortunately, I had to start towing almost immediately with approximately 1,000 miles on the truck when I first towed the Airstream. I was getting 9.6 MPG's at 75 vs. 12.6 with my '05. I requested an update on the programming with a tilt toward towing at that speed. That got me an extra 1 MPG to 10.6 MPG's.

This past week I decided to tow at 70 to see if there would be a difference. I towed 455 miles on the interstate only stopping for one meal and once for fuel and another for a rest room break. Other than that I kept the cruise control on 70. I got 10.5 MPG's. I actually lost .1 MPG's by decreasing my speed by 5 MPH. That is not scientific of course and there were probably other factors that would have impacted the fuel mileage, but I don't know what they could have been. For once I didn't have to drive through any significant amount of rain that would have slowed me down as is the norm on these trips. I'm not saying that justifies the speed, but this is a stretch of interstate that I travel 4-5 times a year and know where to take it easy on the rough sections (heading south) and where I can safely go faster. Traveling the same stretch of interstate is so boring is the main reason I go with the flow. That extra 5 MPH trims nearly 45 minutes off the travel time and that's a lot of time when you are fatigued from sitting behind the wheel for 6 plus hours with a bad back and looking at the physical demands on that aching back with all the bending over to set up camp.

With the Airstream in tow, the main problem is finding an opening to pass cars in the right hand lane that go 65 or slower, not to mention semi's that slow down on every hill and speed up on the down side. All the other traffic wants to go 80 or more and going 75 seems like I am in their way when I try to pass. Also, the right hand lane is dominated by tractor/trailers and they beat up the road surface pretty badly so I feel the center lane is less stress on the tow rig/Airstream combination. As my Airstream tires age I will slow down and may do that anyway to save on fuel...if I can find a speed that will save any. I do plan on replacing my tires earlier than most people recommend just to be on the safe side.

[fotochop]

- as a Zen master I find journey as interesting as the destination ;-)

OK, the real reason I tow at 55 is because of my 8 yr. old in the back seat...and my single axle trailer...and the mileage...and...

[Mikethefixit]

Minnies Mate
What rear end ratio does that thing have? I have a F350 PowerStroke 7.3 with a 3:73 ratio and an getting about 17mpg average. Now we are both retired but when we did the two short trips this yr The average included a week of city driving also. If your ratio is 4:10 U will never get good mileage. U need the RPM's at 1650 to 1850 for mileage.
U can get chips for that computer that will not affect the warrenty.
But don't really expect great mileage before U reach 60K miles is about the time that engine is broke in. Be more careful on the jack-rabbit starts and trying to reach terminal velocity in 6 seconds. Diesels don't come up to speed like gas engines. Thus when U do this little meaningless things they adversely affect fuel mileage and 60 to 65 mph max tow speeds will increase it also.
I'm not just trying to blow smoke at ya, I have 45 yrs with diesels OVER THE ROAD not including my young yrs on the farm.
Best of luck to U
Roger

[Minnie's Mate]

Thanks for the advise Roger. I am not real familiar with diesels as this is only my second. My first didn't have the initial get up and go that this one does, but then it only had one turbo and not the twins that this one has. I know part of the loss of mileage is the particulate burner in the exhaust system and part of it is just the ULSD fuel. My first diesel was a 6.0 and tach'ed the same pulling the Airstream at 75 as it did at 55 because of the final shift point. I haven't towed as much with this one yet so I haven't found it's sweet spot.

Right after I bought this truck, I stored my Airstream in central Florida where all of our trips for the first half of the year would be so I wouldn't have to drag it over the same roads time and time again. This turns out to have saved about $100/trip over four trips plus one to two hours on each leg of each trip. We have a couple of rallies coming up here in Georgia plus the Labor Day Weekend at a nearby State Park so I brought it back after this last trip to have for those.

I have reservations about the programmers that are available on the aftermarket. I'm not familiar with replacement chips other than having seen motorhomes advertised with Banks chip sets along with Banks exhaust modifications and Banks air intake systems. I assume you can get new chips from Ford (?). I did ask the dealer's shop to update the programming several months ago and that seemed to raise my mileage from around 9.6 to 10.5 MPG's.

I have the 3.73 rear end...or at least that is what the paper work says and it is 2WD and not 4WD. With my first diesel truck I was getting between 19-20 MPG's on my daily commute (again 3.73 2WD). With this truck I get around 17. I figure I lost 2 MPG's both towing and non-towing. But my back sure appreciates the re-designed seats of this truck over those that were in my '05.

[norsea]

Originally Posted by Minnie's Mate

Thanks for the advise Roger. I am not real familiar with diesels as this is only my second. My first didn't have the initial get up and go that this one does, but then it only had one turbo and not the twins that this one has. I know part of the loss of mileage is the particulate burner in the exhaust system and part of it is just the ULSD fuel. My first diesel was a 6.0 and tach'ed the same pulling the Airstream at 75 as it did at 55 because of the final shift point. I haven't towed as much with this one yet so I haven't found it's sweet spot.

Right after I bought this truck, I stored my Airstream in central Florida where all of our trips for the first half of the year would be so I wouldn't have to drag it over the same roads time and time again. This turns out to have saved about $100/trip over four trips plus one to two hours on each leg of each trip. We have a couple of rallies coming up here in Georgia plus the Labor Day Weekend at a nearby State Park so I brought it back after this last trip to have for those.

I have reservations about the programmers that are available on the aftermarket. I'm not familiar with replacement chips other than having seen motorhomes advertised with Banks chip sets along with Banks exhaust modifications and Banks air intake systems. I assume you can get new chips from Ford (?). I did ask the dealer's shop to update the programming several months ago and that seemed to raise my mileage from around 9.6 to 10.5 MPG's.

I have the 3.73 rear end...or at least that is what the paper work says and it is 2WD and not 4WD. With my first diesel truck I was getting between 19-20 MPG's on my daily commute (again 3.73 2WD). With this truck I get around 17. I figure I lost 2 MPG's both towing and non-towing. But my back sure appreciates the re-designed seats of this truck over those that were in my '05.

Hi Minnies Mate,

I too am the proud owner of a new F250 Powerstroke. I too have the 3.73 rear end but I have the 6 speed manual gear box.

I can say, based on my own experience, that the Lie-O-Meter that calculates fuel mileage does not work worth a hoot.

I have recorded mileage and gallons purchased since we bought the truck new some 17,000+ miles ago last November. We've been across the country from Oregon to New Jersey, south to Florida then west to San Diego and north back to Oregon. NEVER (strong word) has the Lie-O-Meter come close to the computation of miles divided by gallons of fuel pumped into the tank.

The Lie-O-Meter ALWAYS tells me I am getting MORE MPG than the actual computations produce. That makes matters even worse if you are not happy with the fuel mileage.

I spent a lot of time hanging out on Ford Powerstroke forums learning as much as I could about the new Ford diesel prior to our purchase. From what I have read, I would be very reluctant to change anything associated with the emissions controls on these new vehicles. It has been stated by those who have changed the computer chips in their vehicles that Ford voided their power train warranty as soon as this was discovered.

Apparently the new vehicles do have the capability to record when a chip is taken out and/or put in. I understand that previous year models did not have this capability. It also notes that a non Ford chip was inserted.

The same is true for those who made changes to the exhaust.

So, I would be VERY conservative about making modifications of this nature. I have asked my local service department folks about doing changes of this nature and they have stated that the voiding of the power train warranty is a very real issue.

Apparently the EPA is very serious about ensuring that clean air wins. I could be wrong.

Jim

[Minnie's Mate]

I've always felt that the engineers in the white coats at the design centers knew what was the best compromise on issues of fuel/air mix and figured the same was true with diesels so I really didn't feel comfortable with aftermarket programmers. A buddy of mine kept telling me I should get one for my '05. He told me it would make my '05 sing and dance and do all kind of special things, and I told him I wasn't going to do anything 'till the warranty ran out and then I'd think about it...not. Well, I traded before the warranty ran out.

Chips are a whole new thing for me. I know nothing about them or how they would be different from the programmers. I have 15K miles on my truck (we've done a lot of camping in central Florida already this year @ 900+ miles each trip) so I still have a ways to go on the warranty and I'm not going to do anything to jeopardize that. I'll have to do a lot of research before I make any changes to what could be a potential $5K transmission job or $10K or more engine job. I don't know for sure what they cost to replace, but the numbers I've heard are really scary.