Summer of 1983: 1,190 miles in 21 hours (all Autobahn) with my CB 750 from Barcelona harbor (coming from Ibiza) to West Berlin (having to go through East Germany, being with Berlin Brigade), and with my wife as a passenger.
I thought I lost it, but:
October 2013: 960 miles in 17 hours with my BMW RR from the U.S. Regional Medical Center in Landstuhl, Germany, to Aosta, Italy (mostly Autobahn but also driving the Grande Saint Bernhard Pass) and back due to a failing exhaust cam shaft (the intake cam shaft had been replaced three months earlier).