With the clock showing 7’32.44 minutes, Horst von Saurma, Chief Editor of the German specialist magazine “sport auto,” achieved a new record for road-approved vehicles, at the wheel of the 612 HP strong Porsche. He completed the 22.6 km long round in the Eifel at an average speed of 164 km/h.
source
http://www.fastdrive.org/news.php?extend.185