All Temps were fine when towing. The engine temp when up a little but came down quickly. I have a video of the gauges it's a little shaky as the truck was moving around with the wind and I was driving with one hand. It shows me driving at 2,000 rpm then flooring the truck and the rpm went to 2700 but no change in speed. Outside temp 97. I can post this vid if someone tells me how.
I took my daughter camping, just the two of us so you will like the choice of music on the vid!

 

Not sure with this site but might be easiest to upload to YouTube or Vimeo then just post a link to it.

I should have an Edge CTS installed by Monday so I'll shoot video going up the hill out of Camp Verde.

 

There have been folks with faulty torque converters, your last comment (post 46) certainly points to this.

Might explain a lot, normal behavior until loaded, problem would surface under stress.

 

This is exactly what I was thinking. There is no other explanation in my mind.

 

Here is a link to the vid.


2011 Ford F250 6.7 Diesel Gauges pulling a Hill - YouTube

 

Couldn't tell for sure, which hill is that, north bound out of Camp Verde?

 

Going out on 260 up to 87 on the rim.

 

It looks to me like you were pulling the maximum speed limit for trailer (ST) tires up that hill, can't safely go any faster as the ST tires are not rated for it. In my state (WA), you are limited to 60 mph with ANY size trailer, so it must be refreshing to at least be able to go legaly a little faster. On the flip side, the engine sounds healthy and I would think that the truck wth 8k should pull better than 65 - safely or not. Did you have a heavy load in the bed at all? Quads, ATV's, full load of heavy Americans?

10mpg sounds about right with that load - we in our various fleet trucks get down to 7 mpg towing, but can get over 20 mpg unloaded on some of the trucks.

David

 

I am going again this weekend. I will take another vid. It seems other people are noticing the same thing. Ford seems to have detuned these trucks when pulling a hill. It may be an EGT trigger point or some other electronic monitoring but they sure have taken power away at higher speeds.

I was just guessing but the motors have the exhaust coming out where the intake usually is. I thing this will put a large amount of heat where there usually isn't that much. Are they trying not to burn anything like the hood or electronics on the top of the motor?

My Ecoboost 150 would literally run away from this 6.7 at Highway speed pulling a 6% grade and 8,000 lbs. They did not limit the Ecoboost like the 6.7 Why?

 

I really hope they did not limit this truck, that would suck. On the other hand it would be good for you Shelby because it would mean nothing is wrong with your truck.

Seems odd to me that they would limit the power when towing on a hill, but not limit the power when towing on level ground. What is the difference, why the limit in one place and not the other? Beats me...

 

The limit is normaly exhaust heat or EGT's. Ever watched a newer semi pulling g grade, and they are moving right along, then all of a sudden they slow down? Well they have reached the EGT limit and HAVE to pull there foot out of it or risk damaging the engine.

Remember, rarely is full or close to full throttle used for miles on flat land, but it is used on grades, and that is a lot of horsepower, fuel and heat to deal with.

So Ford has detuned there diesels for some time in the larger trucks, the same engine that is in the F250/350 is derated in the F450/550 for example.

Why? because the 400hp that Ford advertises is a IMTERMITANT rating, and is NOT sustainable on a continuous duty rating. This is a normal thing with diesels. While not published, I would imagine that the continuous duty rating s much closer to the 300h mark, but that does not sell, PEAK numbers do.

EDIT: this is not just a Ford thing, GM and Dodge have to do the same, else have a much lower advertised rating.

Same even on a semi duty engine - a semi engine can get 400 - 450 hp out of 14 to 16 litres, on a continuous duty rating, or up to 650 hp on on a intermitant rating.

Think of it another way, if a Hemi can pull 4000+ hp down the strip, why not all the time? Because yes, while it can pull well past 4000 hp on the strip, it does this for only a few seconds and then is rebuilt.

A much more sustainable and usable hp for the engine is in the 350 - 500 hp range.

As such, even military piston airplanes were rated much the same, in WWII there was a normaly used maximum throttle setting, then a higher throttle setting that could only be used by pushing the throttle quadrant thru a safety wire, thus breaking it. If this setting was used, you were in imediate danger of being killed, etc, and yes, there was a good chance, if not guarenteed chance of engine damage as a result. The broken wire let the ground crew to give the engine extra care / further diagnosis.

Interesting reading the old logs, it seems that most of the pilots never even felt the wire break as they were concentrating on saving themselves or a fellow flier....

Diesels have had for years the following established ratings. Gas engines back in the day also had much reduced HD ratings.

Light duty - non continuos rating, limited by total miles / hours / GVW & GCWR per year, exact specs depending uopn the manufacture. (This is the highest horsepower rating, the one that sells trucks) That's use a 400hp example, but that is just a example.

Medium duty - non continuos rating, limited by the same limitations as the light duty rating, but at higher limits. (This rating does not sell as many light trucks, but this is the one that the medium duty truck people look at) This rating for example might be at 300 - 325hp for the same 400hp engine as listed in the LD rating

Heavy duty - Sustainable, continuos running, day in day out, regardless of throttle position. (This is the rating ignorant people just do not understand, but it is the TRUE horsepower that can be used all the time) This might be somewhere in the 200 - 250 hp range,

But these are just some number for example, not gospel and do vary from engine maker to engine maker.

Same for gas engines back in the day, take one look at the compression ratios - all Ford medium duty trucks had compression ratios in the 7.2 - 7.6 range for there MD & HD engines. LD engines had what, 8.5 - 9.5. WHY? Because those high compression ratios led to extreme heat build up (combustion chambers) which led to detonation while foot down slogging up a hill at 15 mph loaded. Backing ther ignition timing did little as then the timing would be so retarted to keep the detonation in check that the engines would not run right.

So things are built a way for a reason, somethimes I will admit for reasons that are purly profit driven, but in this case it really is driven by a engine usage and service life criteria.

Just food for thought

David

 

Great write up David. This makes me feel good about the engineers that built our trucks. They made sure they were built right and won't leave us stranded on the side of the road if we do not know what we are doing.

I guess 65mph is enough and I will be happy that my truck can do that while towing 10k+ lbs up a 7% grade.

 

It looks like you were in Tow/Haul mode, try taking it out....as well as the suggestion for manual mode. Just a thought.

 

Dealer told me to try the same thing. He said put it in manual and try changing gears. While I don't think it will help I am going to try it!

 

In my opinion the 7.3 was the best motor for towing, and just every day driving, mine has 900k miles on it, still runs like a champ, just had to replace a head