I ran a 99 psd for 13 years. From that you can see that I do not get in a hurry if the wheels are turning. I was looking for change did some research and ordered a 2 WD F250 with the 6.2. It tows a 11.5K fifth wheel.
I will always remember the first trip we took off on and the wife remarked, "wow we can even listen to the radio in this truck."
I am happier than a pig in you know what with the 2012. It will definitely out yank the 99 diesel but that is apples and oranges.
I normally get 8.7 towing at 65 mph. We just got back from SC to IL dead heading since we left the fifth wheel in SC for later on this winter. I ran it on at least 75 all the time and it knocked out 14.6 mpg.
Sometimes i think i would be better accepted in the community if I re badged it as a gasser in diesel clothing. :B