I think Google avgs for 55 mph, I just checked - 540 miles per goog door to door, done in 8.25 hrs = 65 mph avg.
I made two off and on stops, both pretty quick, fuel for car on one, fuel for me on another and one I-80 rest area splash and dash
Take off 20 minutes, avg goes to 68 mph, sounds right. Did long stretches at 80 mph. There were some miles of one lane
construction zones but traffic was light and we rolled thru them at constr. speed limits, usually 55. I also timed my departure
to miss rush hour in Westchester and Stamford, no traffic jams the entire drive, LUCKY! Avg was probably around 70, which
seems more than reasonable, had some very long stretches near 80, good wabbit huntin' ha a a a a a a