Mike Up

Try to test drive a 2010 5.4L Screw 4WD with the same model, features, options, "AXLE", and bed size and the real difference will leave no question. I did just that. Both trucks had the same axle and were within lbs of each other. There's a reason for that much higher tow rating.

Read my review here. BTW, there are dynos but no back to back, apples to apples with same configuration, on the same day, on the same dyno. Only 5.4L are questionable at best and most reliable one was done at 4500' with 85 octane. It actually was the only 5.4L with the newer 2009 & 2010 body style with the 6 speed transmission. That dyno showed very low because of low octane and high elevation testing. After I corrected for elevation alone without touching the low octane, this brought the torque curve above the 5.0L at lower rpm. Still the dynos used for the 5.0L were different, different day, different YEAR, oranges to apples still, still could not be used for any meaningful comparison. One thing is for sure, the HP is better on the 5.0 as it really goes once it's wound up where the 5.4L did not. Another thing for sure, the 2010 5.4L has instanteous torque that was absent in my 2011 5.0L drive.

Loki 5.0

Here are Dynos graphs that have not been manipulated. Understand that this type of dyno reads low compared to others but the charts are very good for comparing http://www.5startuning.com/5.4L%20V8...ans/index.html

http://www.5startuning.com/resources...150-5.0L/3.jpg

It is obvious which motor has more low end torque.

Mike Up

Here's some actual dynos for the 2009 - 2010 5.4L with 6 speed transmissions. The actual truck we're talking about and not an early one with the inferior and power draining 4 speed trans. These are not dynos done where they can't even be compared because the torque is not accurate at lower rpms especially where torque shows 0 ft #s at 2400 rpms and below, where torque counts the most.

1975Pete

I agree with what you are saying here, the engines are not in question, I am plenty confident that they can pull the trailer. I guess what I am trying to figure out is why did Ford "downgrade" the rating from 2010->2011 for the roughly the same truck. I am comparing a SCREW, 3.55 rear, SB, XLT, tow package (not the MAX tow package). The only difference I know is the engine changed from the 5.4->5.0 and there is a tranny difference. *Can this account for a 1,900lbs towing capacity difference?*

But even looking at the official Ford towing guide there are only a few things that matter to it for tow rating: engine, gearing, body style,wheelbase, and 4x2 or 4x4. It doesn't have option for XLT,FX4 which I know have spring differences.

I know the sales/marketing dept of the big 3 like to play numbers games to be on top of the biggest/best truck competition. So I seriously doubt that Ford would downgrade a tow rating for a very similar selection based off their matrix above.

Just trying to make sense of the shifting numbers.

Loki 5.0

Shake your head Mike your eyeballs are stuck. The link I provided is a 2010 5.4 6 SPEED TRANSMISSION. Everybody who has owned both knows which motor pulls stronger from idle. Your little test drives where you confused the drive by wire characteristics of the 5.0 with low speed torque have skewed your perception. Pull a loaded trailer on a incline in 6th gear @ 1500-1700 rpm in cruise control with both engines and you will understand what all the hype is about.

jswd60

Cant agree with you more. I just picked up three bales of hay this weekend. 1500lbs each and 2000 lb trailer total of 6500 lbs. Truck had way more acceleration than I needed, I never got above 3000 rpm when accelerating up to 65 mph. It stayed in 6th the whole time until I got into some hills and a 30 mph wind in my face. Then it only had to shift into 5th and on one very steep hill 4th, but it maintained 63 mph on that climb. It would stay in 6th going over hills with a crosswind, but had to downshift into a head wind. Over the 100 mile trip I averged 14.3 mpg. Without that wind I could have easily managed 16-17 which is what the 5.4 guys are getting
UNLOADED

The truck could have easily handled another bale if I had a long enough trailer. I am very impressed with this truck and I would not hesitate to tow any load at any time (within the weight ratings).

GatorMedic

That's not really saying much. A lot of people that went from 04-08s to 09-10s have said there is a night and day difference in towing. The six speed transmission makes a big difference

xdrockstar

Right, I agree with the OP in this thread but other people are saying there is a "safety" difference which is basically false.

1975Pete

I went thru this thread again to see the safety claims, and I really did not see anything specific. What safety claim are they saying? I really do not think the engine itself is the factor. But, like you mentioned, the brakes, suspension, hitch receiver, will be more real factors.

But my original question that I started this thread with remains unanswered, though. But I suspect it will be a vague guess as to how Ford determines its numbers. With no really solid reason why there is such a large difference.

iluv2fly

I have owned to fords with the 5.4 and currently still own one of them. I just bought a 2011 F150 supercrew with the new 5.0 and it will blow the doors off of the 5.4. It has more torque and hp. Yea the 5.4 might be better right off the line for 5 seconds but after that it is history the 5.0 leaves it in the dust.