Here are a few fun videos on the 2011 Superduty .....

The 2011 Ford Super Duty Trucks | The Official Site of Ford Super Duty Trucks

 

Good propaganda but the reality of the 400/800 flash was a hyper drop in MPG. I and everyone else went from 18-20 down to 14-16 and the tranny shifts like it's getting kicked by a donkey. In short: I hate the 400/800 flash it turned my truck into a piece of shet that I lament buying.

 

Sorry to hear that - dissapointing to say the least.

 

Yeah, I'm pretty sour on the truck. At least you didn't pay $52,000.

I spend most of my time on the road in my 300ZX though so life is good.

Honestly, I'd dump the 6.7 if It didn't mean taking a bath on the resale.

 

just my 2 cents on the 400/800 my buddy has one with the new flash and they are pleased with their fuel mileage. they are getting 23-26 depending on how fast they are going. and the power is great!

 

Now wait a minute...

You had a thread in the 6.7L forum complaining about this, and only one guy came forward and said that they had the same problem. Everyone else was telling you that there is a problem with your truck, not the flash.

https://www.ford-trucks.com/forums/1...7-problem.html

And now you come here venting about it and telling people that all of us are having this problem?

I live in NW Wisconsin, and have been running winter blend fuel since November. My fuel computer has proven to be within 0.5 MPG of actual, and right now I'm at 18.9 MPGs for the tank. Yesterday I was at 21.5 MPGs going to work, and 20.6 MPG coming back.

And I have the 400/800 flash.

Something isn't right with yours, but that doesn't mean all of us have the same issue.

On edit:

Here's my MPG data since November. Note the low average due to the trip I took with my trailer in December. Click the link and you can see every tank:

 

That's way too high. Did he get this number off the 'lie-o-meter' ?

 

Right, initially people said it was a problem with mine and only a few others had seen that problem but subsequent posts (including the fuel mileage poll) seem to show a trend of low fuel mileage and harder shifts. You're right in that mine might be worse than other peoples (it's a subjective call cus I can't drive theirs to see) but based on people's posts (which is all we have to go off of) my problem is far from unique. That and somebody posted some details about build date and what version of the flash you got based on the trucks build date so that could very well be the difference.

That is a cool link by the way. I love the way you have mapped everything out so well. but you're at $3.50/gal DANG! We're at $3.18/gal here. We may very well have different driving styles but I went from 21 from the factory to 16 after the 400/800 so...

And again you're right it may very well be a problem with mine and the other people who have the problem but it doesn't change the fact that it's a real problem and Ford refuses to do anything about it even after many escalations. So I've gotta stick with my statement about the 400/800 flash being a bad thing. I hope the new flash (This/next month right?) fixes it.

 

Harder shifts maybe, but I haven't noticed much difference.

Fuel economy can vary widely depending on usage. For example my fuelly link above shows an average of 14.3! It's really better than that if you throw out the 10-MPG towing I was doing.

Driving habits also account for over 25% variance in fuel economy, as those who brake frequently see lower MPG numbers. It's very hard to compare my numbers, which are predominantly highway, to someone who lives in an urban area and rarely sees highway speeds.

So yours is a good example of a fuel economy problem, demonstrated by a noticeable decrease across the same driving conditions. Who, other than Thom12, has claimed such a problem?

Seriously, if it's more than you two I'll get in touch with a contact I have at Ford for him to take a look. But please don't bash the entire engine and flash because you and maybe a few others have seen a problem.

 

My only source is/was the fuel mileage poll thread from a while ago. I think I should clarify: the truck is great but the flash is what I hate.