ShinerBock wrote:
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.
My brother has a 2012 F350 SRW and his lifetime average is around 13.5 mpg which is inline with most averages on fuelly (LINK). We also live in the San Antonio area as well and he only tows his 10k travel trailer down to Rockport a few times a year. I remember him complaining of his mileage dropping after a few years of owning it as well and I believe it is still the same way.
Although many things decrease your fuel mileage during the winter like winter blends fuel that was already stated and even the cold air itself. Air becomes more dense as it gets colder and if I recall correctly from one of the fuel economy studies at Cummins, aerodynamic drag increases by 2% for every 10F drop in air temperature. Going from 80F fall weather to 20F like what we have had the past few weeks in the San Antonio region would make for a 12% increase in drag which is inline with the amount of fuel mileage you dropped.
My trucks fuel economy increased a little at around 60k miles and has been steady ever since to my current 137k miles.
