Originally Posted by
mx409
Are you saying you have never got better than 12mpg? What do you get consistently?
16 city, 18.6 highway at 65mph. Hand Calculated... Mine is a 6.4 PSD though. I didn't notice the first time that you said you had a 5.4l. I had a 2008 F150 with the 5.4, and got 17mpg at 65. The F250 is a lot heavier truck than the F150, so I could see you getting around 15mpg at 65mph.