2016 Ford F-350 Crew Cab LWB Dually 6.7 Mileage

[Texas_Roadrunn1]

Our 6.7 liter truck mileage has dropped from the 14-16 mpg range on the highway to around 12-13 mpg when not towing. Truck has about 35,000 miles on it. We have seen mileage in town as low as 10.5 mpg. We have a K&N air filter which has been recently cleaned and we have added Power Service Diesel Kleen Injector Cleaner and Performance Improver to our last tank of fuel without any improvement. Has anyone had similar experience with the Ford 6.7 liter diesel. If so, what was your resolution? Our dealer doesn't seem to want to confront the issue. Thanks in advance for your help.

[Cummins12V98]

First think go slap whoever suggested you use any oil type air filter!!! They are notorious for messing with sensors on newer diesel trucks and auto's with sensors in air intake.

They could deny you warranty for having a non approved filter.

There is NO reason to use such a filter on any of the newer diesel trucks!!!

Class Dismissed.

[rhagfo]

bucky wrote:
Winter blend in your area?

X2
Winter blend is normal #2 diesel with #1 diesel added prevent gelling, #1 is less efficient.

[bucky]

Winter blend in your area?

[DanNJanice]

In addition to post about excessive regens, which could certainly cause your issue.
Did one of your gas stations recently switch to bio-diesel? I am told that bio-diesel is not quite as efficient as regular dino-diesel.

[LIKE2BUILD]

Texas Roadrunner wrote:
Our 6.7 liter truck mileage has dropped from the 14-16 mpg range on the highway to around 12-13 mpg when not towing. Truck has about 35,000 miles on it. We have seen mileage in town as low as 10.5 mpg. We have a K&N air filter which has been recently cleaned and we have added Power Service Diesel Kleen Injector Cleaner and Performance Improver to our last tank of fuel without any improvement. Has anyone had similar experience with the Ford 6.7 liter diesel. If so, what was your resolution? Our dealer doesn't seem to want to confront the issue. Thanks in advance for your help.

Not a Ford owner here but measurable changes in mileage definitely mean something is going on. Are you seeing more frequent regen cycles lately? If the ECM thinks the DPF is plugged it will go through regens to clean the media of particulates. That is a fuel consuming process and could be one explanation for the decreased economy.

KJ