My 2008 model 250 4wd diesel gets 15 in combination driving and 17.5 on the highway. I have not recently checked towing. My truck now has 12,000 miles on it and the mileage has really improved--despite it being winter. I suspect 1-2 mpg more would be possible in warmer weather. This is quite an improvement on the 6.4L economy when I first bought it, telling me that these engines likely need a substantial break in time for maximum fuel economy. It also is almost exactly the same mileage (if not slightly better) than my 7.3L diesel PSD in my 2002 model in "real world" driving. My current rig also weighes almost 8,000 pounds empty and I am not a slow driver. When the new Ford's came out, there was concern about the mileage (on my part also), but I am not so sure in many cases if the engines were so new they were not properly broken in. In any event, that is my number. I suspect 19-20 highway will be possible in warmer weather with a few thousand more miles. I do not think my truck is quite the equal of the Cummins on fuel, but the equivalent truck weighes almost 1,000 pounds more empty, which accounts for some of the difference.
John M
