Rich&Yvonne wrote:
I have the 2008 with the 6.0 and 3.73 gears. We just came back from a week long road trip from Florida to Kentucky and back. We averaged 9 to 10 MPG loaded. I found using tow/ haul mode and "manually" locking out 6th gear it would run between 2200 and 2400 RPM in 5th gear at 62 to 65MPH. It would jump to 3000 - 3200 in 4th gear climbing the grades, dropping down to sometimes 55 MPH.
Empty around town I still only get 10 MPG and around 15 highway.
I get similar milage with the same truck basically except on a trip to northern Wisc. last fall I got between 10 and 12 going up and coming back with wind. I keep my foot out of it tho.