Keep it at 65mph for the first 1000 miles or so and then keep it sane for the next 5k or so. a couple long trips help things break in a little better, when I got my 04 I put 3500 miles on it in under 3 weeks, I just went where ever I wanted. short trips do nothing for break in so keep that in mind. just remember you bought an awesome diesel truck, not a 500hp Mustang. Enjoy.

 

Yeah I did about 1,000 empty miles running 55-65 mph, you will see a lot more power than the old 7.3 and yes the new engines are super quiet. with over 100,00 miles mine is still quite as a church mouse, exhaust pipe still clean as the day I bought it. If you delete the emissions you have voided any and all warranties, and are in violation of federal law. I know a lot of guys do it....and get away with it, but a lot of people drink and drive too. So ask a lot of questions, before removing it