The total value of the cars is estimated to be £8.5million, which included a very rare Pagani Zonda R, one of just 15 that have ever been produced with a price tag of approximately £2.5million.
Kharitonin closed the track for two days in order for the billionaires to play with their toys.
Abramovich also brought a Ferrari FXX, a Bugatti Veyron, a Ferrari 488 GT3, a Mercedes-Benz AMG GT3, a Lamborghini Reventon and an Aston Martin Vulcan.
A Nurburgring instructor, Tatiana Golovlyovo, said: "Usually track days are organised for the owner of the Nurburgring, Viktor Kharitonin. This is an exclusive event for the owner and his friends, nobody else (apart from the staff and crew working for event) can enter the property."
The second day involved the shorter GP Strecke, which spans 3.2 miles.
The Russian moguls also tested the entire range of the Porsche sports cars and the single-seated "Formula-BMW" vehicles throughout the event.