I got 72 from Portland to Seattle in my VX last summer. Lower 70s are pretty average for me on that trip. 63 is impressive but lose the Amsoil and maybe you'll break 70 Save a few bucks too
Too short a trip to really be accurate though.... What oil do you use? Why you say lose the Amsoil?
I know a guy personally who has gone over a million miles on his Jeep and never had the engine rebuilt, using Amsoil.
a reliable source tells me there was a volvo(i think) recently retired in wisconsin with 3.1 million miles, also original drivetrain. had amsoil its entire life(after break-in).
the guy put the car down due to rust(frame) as he felt the car was dangerous to drive. certainly he got the most out of that one.