This: Attachment 356233
"Hypermiling" experiment. Near Leominster MA to Tenafly NJ. End of run is 31.2 on trip computer, adjusting down 3% from my stock tire size to the 255/40/19 Michelin PSS I run now gives a corrected 30.2 mpg. 201 mile trip, filled tank at start, have about 9/16 tank left (9 gallons) left. I saw 31.7 crossing into NY on the Merit Pkwy. Yes, I have previously checked my trip computer with fillup amounts and it is dead nuts on.
I generally get 22-24 mpg.