I had the luck to be on a DC-10 in the 90's that had a block time of 5 hrs 20 mins between Miami, FL and Paris, France. IIRC the 'normal' flight time was around 7.5 hrs and the advantage was won through an unusually fast jetstream. This was sometime in the month of March. I vaguely remember the figure of 'over 200km/h' being mentioned.
For once it worked to my advantage and i was able to take a previously unworkable connection and saved myself half a day of waiting around the terminals in a jet-lagged stupour
Regards
SHJ