I have a 08 F350 CC KR SRW 4X4 and haul livestock all over Montana and WA. OK, so here's what I discovered by accident, my truck is completely stock, however i do have some of the wires from the PCM connected to my upfitter switches, one is for elevated idle to charge batteries, one is connected for PTO and the other is the idle control for the PTO. Generaly I never use them, but by accident I left all three on and drove from Bozeman MT to Seattle yesterday, hauling my stock trailer with about 3/4 full of live stock and I swear to GOD! my truck hand calculated, got 13.8 MPG the computer said 14.2 mpg. The trip between MT and WA is lots of high mountain passes and speeds around 75 mph. My truck has 19k on it and the best it ever got was 9.8mpg. Now I dont know if its because of the switches and all these compnents being on, I thought they only actictivated when the truck was in park and the e brake on, I am thinking that it must do something, just not sure what, all I know is DANG! those switches are staying on. I will let you know what it does without the trailer.

 

OK I'll be the ginny pig, Which wires from the PCM are hooked up to exactly which switches?
Do you have a PTO installed on your truck?
what gears are you running?
Did you have a strong tail wind?
19K- ask some gurus, is it broke in yet? Who would know, you've got the most I've seen posted in awhile. Today I noticed i was doing better and only have 1200 on it, it's avg-ing better than when it had only 300 miles.

 

Did it start running better too??? I was once told these 6.4s have a "break off" chip, where the truck is basically detuned untill so many miles, Ive heard from a few people that said there truck really starting running strong at around 8k. And possibly the fuel economy jumps up as well.

 

I have +/-18k on my 450, I cannot say that it really started running better at any point yet. I will say that my mpg has gone up about 1mpg since 10k or so.

 

What, who says that? Are you pullin my power stroke?

 

That was also what one of the "salesman" told me also about the truck but he told me 80,000kilometers. His comments were that it was detuned up to that point. Had to take it with a grain of salt.

 

I would have to agree with the motor breaking in theory. Back when my 7.3 was new it made a big difference at about 15000 miles( 3points in mileage, reved better). Our 08 only has 8500 miles yet so this is good news.

 

All I did was ask my grandfather where that hill was that he used to get to school everyday... now I only drive it in the opposite direction.

That's right... down hill, both ways. Boost never gets over 5psi.

 

My 08 has 68,000 miles showing and still runs like crap and mileage is still at 7.6-- its the regen and DPF -i removed it at 21K and it ran greay for a week and a half but then started blowing out loads of white smoke - so bad that people were pulling up next to saying that my trailer was on fire- but mileage went to 13.6 :"( i need to kick this crap out a here but the government has made it very difficult to do with this one.

 

I have a secret to better MPG. Buy any other Diesel other that FORDS! There is no excuse for this MPG. The new huge Benz SUV gets 24MPG!

 

"Buy any other Diesel other that FORDS! There is no excuse for this MPG"

You are right my dad has a 03 Dodge 3500 Automatic with a heavier trailer than mine and he gets --- are u ready ? 14.6 MPG I am lucky to get 1/2 that. I am almost ready to buy a dodge cause the fuel savings will pay the payment since it seems like it is going over 3 bucks a ding everywere.

 

Dear god!!!! 68k already? there only a year old......

 

but thats an 03 and ALOT less emissions. What kind of mileage do the new dodges get with all that emissions junk on there?

 

Who cares its a Dodge!

 

Thats right now your talking apples to apples, the problem is the new emmissions control. Don't blame ford, dodge and chevy are having the same problems,most people can see this.