I'm really glad that I went with the 4.30's. I had 3.73 in my last superduty, and while it did the job, it was a little sluggish off the line with a load.

I'm a little over 2600 miles at this time, and on my 50 mile trek to work this morning I was getting 14 @ about 65-70mph. I really haven't been worried about fuel mileage yet. Just been driving it hard and breaking 'er in properly.

At the beginning I was getting less than 12. It has been steadily increasing as the miles add up. I'll be content with 14mpg empty when it's all said & done. That is until I follow Matt's lead and apply some tuning to it.