McLaren driver Lewis Hamilton has admitted that his team need to find out why his car was slower in the second practice session for the Korean Grand Prix than it was in the first.

Hamilton topped the standings in the first practice session but he slumped to eighth place during the second, and the 27-year-old was unsure as to why his car didn't perform.

Hamilton told reporters: "The first session was great but I don't really know what happened in the second session.

"We need to analyse what went wrong. Maybe the wind direction changed a little bit but it didn't seem to effect the other teams."

Hamilton announced last month that he would leave McLaren at the end of the season to join Mercedes.