just an update, i had posted my new superduty diesel was only getting 11-12mpg off the lot, well 6,000 miles later shes pushing 17-18mpg's highway. thats learning to really stay off the throttle in the 65-70mph range at or just under 2,000 rpms. this truck has the average MPG setting on the dash and i spend so much time watching it im affraid when i floor it. ive found that by keeping the turbo psi at or below 10 psi its great on fuel. 20 psi shes getting thirsty and at 30psi up a 1 mile hill on I-84 in ct she was sucking!