Mercedes team principal Ross Brawn has admitted that the team still have problems with their tyres despite victory in the Monaco Grand Prix on Sunday.
Nico Rosberg claimed first position at the weekend, but Brawn has insisted that his team still have work to do in the coming months.
"It is a constant challenge and I wouldn't pretend that we are on top of it. This is a race where you were able to manage the situation without anyone getting past you," he told AutoSport.
"The purpose of the slow start to the race was to manage the situation. We cannot do that at other tracks, so I think we still have a long way to go."
Rosberg's teammate Lewis Hamilton finished in fourth position.