I'm taking my new to me 2011 KR 6.7 I've had it 1 week, to the dealer tomorrow to get them to look at the hesitation on takeoff. I have read on here that not all trucks are doing it. There is 25500 miles on it and have been averging 15.3 mpg empty, is this about normal for what people are seeing? I'm running the 3.31 gear ad I thought I would get better mpg.
This truck was built in Feb. of 2011 would it have the 400/800 settings or would it have to be flashed?
Is there anything else I should ask the dealer to look at or do while it is there?

Thanks in advance
Cliff J

 

If you're talking 15.3 average overall then that's not too bad. I get a bit over 17 overall (town, towing, & hwy) but I don't drive my truck like a gasser either. And that brings to mind the lag that you speak of... these things got a turbo and lag is part of the package unless you spool it up before dropping the hammer, which by the way is a great way to trash the tranny.. A diesel isn't a gasoline engine, don't drive it like one.

 

Sounds normal to me. Try a slower steady take off and slow down. Tip into the throttle and it may respond better.

Shoving the skinny pedal straight to the floor results in poor fuel economy and the lag.

 

my 2012 F250 w 3.31 was getting an overall average of 15.45, over 13,000 miles.
all hand calculated.

highway empty best was 17.8. Towing 7000 closed car hauler I got 10.5.

my 2012 f350 dually, just back from a 3500 mile trip, 1/2 towing 12,000 5th.
got 15.87 empty over 1500 mile at 70-75mph, and 9.6 towing the trailer at 65-70mph (load range G tires, rated to 75mph)
total 12.2 over 3500 miles.
my 08 dually couldn't get 8mpg.

 

No the 15 .3 is just around town and some highway non towing. I just towed to a mule ride this weekend pulling a 11000# rig and got 10.4. I know about the turbo spooling and the deisel thing I just traded a 7.3 for this truck that I did the turbo wicked wheel replacement in that one myself. I do ease into it but this thing still seems like its bad slow getting started.

 

For the 3.31, 15mpg is good.

 

Could this be turbo lag? I'm just asking because the Turbo needs exhaust to get going and produce power so there is a slight "lag" between when you press the goo pedal and the turbo kicks in and starts helping to make power. This is not unique to Ford but all turbos driven vehicles. Some set-ups are more affected than others, but almost all turbos have some sort of lag and the 6.7 Scorpion is no exception.

 

I'm not sure what causes this hesitation but I have 2 friends that have the new 6.7 in their trucks and its not as bad in theirs. One is a 2011 job 1 F350 dulley with 3.73 gears and the other is a 2012 C&C F450 with 4.10 gears.
The other question I had was when did they start putting the 400/800 programing in the 2011 trucks? I'm tring to figure out if mine needs the flash. It was manafactured in Feb. 2011

 

Your friends trucks are gonna seem more responsive because of the rear end gears.. 3:31's ain't for drag racing

 

Touch base with us when you get a diagnosis from your dealership, cliffj59; if you need any assistance from me, I'll be here.

Crystal

 

Basically any truck built after about the second week of August 2010 came from the factory at 400/800 so you should be fine there. Some people call it turbo lag, I call it computer lag. Modern turbo diesels are tuned for clean emissions which means no fuel until the turbo is moving enough air. My 6.0 was far worse, but the 6.7 acts much the same. I rarely ever notice the lag, but I'm not a flat-footer. If you don't roll into the throttle on the 6.7, it is going to act like it just stalled out in the middle of the road.

I'm not saying that it isn't possible that you truck has an issue, but my advice would be to pay special attention to your driving habits and do some experimenting. You may just find the sweet spot without the frustration of a dealer telling you that they can't replicate your problem.

 

Thanks Crystal, I think its great that we have someone on here that actually has some connection to the people we need to talk to.

 

Have you owned a diesel before? Seems like a silly question from me but most engines making this much torque at such a low RPM are "slow" in the first gear.

 

i think its turbo lag. trying rolling into the trottle, keep the rpm under 2500

 

Yea I just traded in my 2000 F250 7.3 for this one. Its probally something i'm going to have to get use to.
I use the truck at work and its about 2 miles around the plant so I do quite a bit of idle to 1000 rpm driving This is where I see the hesitation, its not so bad when i'm on the open road and can roll into it.