new 6.7 reflash by ford = worse fuel mileage

[nordberg]

we just had our truck reflashed at the local dealer last tuesday and we encountered some problems. it took 3 attempts to get the computer to accept the new software. after it finally accepted the dealer said they beleived my computer had a virus but figured the new update would address the problem. on the way home the DEF fluid warning came on saying 730 miles to empty and had dropped to 350 miles to empty by the time we got home ( 60 mile drive). when we got home we put in 2.5 gallons and the warning went out. by friday the urea level had gone from good to 350 miles to empty and fuel mileage went to 14 empty 8 towing. saturday it went a different dealer who thought maybe the truck didnt accept all of the update the last dealer had attempted so the reflashed the ecm again and it took on the first try. now the trucks urea drinking problem seems to have been addressed but the towing fuel mileage is 10 - 11 where it was once 13-14. havent had a chance to figure empty yet but really hope the fuel mileage comes back to where it was.

[richc22a]

Notice any better shifting? More torque?? I have towed two different fifth wheels that weigh identical 15,000, my mileage running 65-75 has been 10-11highway, 9 on hill country curvy mountain roads running 35-60...

[PHXDiesel]

I'd stay FAR FAR away from that first dealer as long as I lived. I'm not sure how they hosed your truck but something was clearly broken with the DEF usage. Who knows what kind of problems that could have caused downstream. Have you noticed more frequent regens?

[jrod350]

mine showed improved gas mileage around town with mixed highway it was 16 16.5 now 18.5 19.3

[miles97]

Just so Everyone knows there is some programming errors that can arrise from getting the update. Ford has even stopped sending out letters to owners. It sounded like they sould have it figured out in a couple of weeks.

Hey PHXDiesel: Don't blame the dealer, all they can do is install the program Ford sends.

[socal2ks]

They said your truck had a virus?

[Sc404]

Originally Posted by socal2ks

They said your truck had a virus?

Maybe it's the Microsoft Sync! Next time ford should use Apple

[BJacobsKR6.4]

I had mine reflashed and yes, there's more power. However I am regenerating 5-6 times per tank!! I drive mainly highway, no idling. It has brought my avg. mpg down to about 14, hand calculated from 16.

[vrsc]

Yep, worse fuel mileage with the new flash

[Sc404]

Well that bites!