Don't know if you're still taking numbers but my 13 6.0l has 19,593 miles, 563 hours and the driving ration is about 65 city, 35 highway. My calculation makes it 34.8 miles per hour; in the upper half of your stats. As an aside, my total fuel is 1801 gal and the total avg is 10.9. When I got the truck last fall it was 10.7, so I must be doing something right.
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