I was reading the expected mileage for the 4.5 litre diesel compared to the 7.3 and it says 25% increase. I know of one diesel owner that says he gets 24 mpg [canadian gallon] on the highway. Could we expect close to 30 mpg with the new engine in our F150's? That would be about 40% better than I get now. I would sure have to consider that engine in a new SuperCrew.