I too am trying to determine what would be a reasonable expectation of milage for my '99 F-350, 7,3 liter Powerstroke. The other responses vary from 16 mpg to 20-21 mpg. That seems like quite a range. My question is how do I get my milage up to the high end of that range or am I just stuck with a diesel sucker?
For that matter, does anybody know a good diesel mechanic for a tune-up/up-grade in North Central Oklahoma?